Method and apparatus for emboli containment

ABSTRACT

Disclosed herein is a catheter for use in an emboli containment system. In one embodiment, the catheter has a tubular body with a metallic braid construction. Two lumens extend through the tubular body, the lumen being in a side-by-side configuration. One of the lumens functions as an inflation lumen, and is in fluid communication with an inflatable balloon mounted on the distal end of the catheter. The second lumen is adapted to receive other therapeutic catheters which comprise the emboli containment system. In another embodiment, apparatus is provided for treatment of a stenosis in a lumen in a blood-carrying vessel comprising a main catheter and a therapeutic catheter. The main catheter comprises a first flexible elongate tubular member having proximal and distal extremities. A sealing element is carried on the distal extremity of the first flexible elongate tubular member. The first flexible elongate tubular member has a main lumen therein extending from the proximal extremity to the distal extremity and exits through the distal extremity. An adapter is mounted on the proximal extremity of the first flexible elongate tubular member. The therapeutic catheter comprises a second flexible elongate tubular member having proximal and distal extremities. An element for performing work is mounted on the distal extremity of the second flexible elongate tubular member. An adapter is mounted on the proximal extremity of the second flexible elongate tubular member. The second flexible elongate tubular member is slidably mounted in the main lumen of the first elongate tubular member. A mechanism is carried by the first flexible elongate tubular member for causing the sealing element to form an occlusion in the vessel proximal of the stenosis to provide a working space distal of the sealing element. A mechanism is coupled to the attachment of the therapeutic catheter for causing operation of the element for performing work in the working space adjacent the stenosis.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of application Ser. No.08/813,023, filed on Mar. 6, 1997, which is a continuation-in-part ofapplication Ser. No. 08/650,464 filed on May 20, 1996, the entirety ofwhich is incorporated herein by reference, which is acontinuation-in-part of application Ser. No. 08/464,579, filed Jun. 5,1995, now U.S. Pat. No. 5,833,650.

BACKGROUND OF THE INVENTION

[0002] The present invention generally relates to medical devices, andin particular, to catheters which can be used in an emboli containmentsystem. This invention also relates to an apparatus and method fortreating occluded vessels in living bodies and more particularly ballooncatheters and balloon guide wires for treating occlusions in vessels inhuman bodies, as for example carotid arteries.

[0003] Balloon angioplasty, and other transluminal medical treatments,are well-known, and have been proven efficacious in the treatment ofstenotic lesions in blood vessels. The application of such medicalprocedures to certain blood vessels, however, has been limited, due tothe risks associated with creation of emboli during the procedure. Forexample, angioplasty is not the currently preferred treatment forlesions in the carotid artery, because of the possibility of dislodgingplaque from the lesion, which can enter the various arterial vessels ofthe brain and cause permanent brain damage. Instead, surgical proceduresare currently used, but these procedures present substantial risks.

[0004] One solution to this problem is the use of a multi-catheteremboli containment system, as disclosed in the above-referencedapplication Ser. No. 08/650,464. As disclosed therein, a treatmentchamber within a blood vessel is formed by two occlusion balloons onopposite sides of a stenotic lesion, thereby preventing emboli migrationduring the treatment procedure. The chamber is created by two occlusionballoon catheters which are slidably disposed with respect to oneanother.

[0005] Emboli containment procedures of this type are advantageous,because they permit the clinician to utilize the benefits oftransluminal treatment in a wider variety of blood vessels. However, theprocedures require the complex coordination of multiple catheters.Consequently, it is desirable to have catheters which make it easier forthe clinician to utilize an emboli containment system. It is alsodesirable that the catheters used in the emboli containment system havea high degree of flexibility, to navigate tortuous blood vesselnetworks.

[0006] Consequently, there exists a need for improved emboli containmentcatheters. This is especially true in the context of the “main”catheter, through which other catheters are inserted and controlled toform the emboli containment system. There is also a need for new andimproved apparatus and methods which make it possible to treat occludedvessels without endangering the patient.

SUMMARY OF THE INVENTION

[0007] The present invention advantageously provides as a main catheteran occlusive device adapted for use in a multi-catheter embolicontainment system. In one aspect of the present invention, there isprovided a catheter, comprising an elongate flexible tubular body havinga proximal end and a distal end. The tubular body incorporates ametallic member, which may comprise a braid or a coil. A main lumen andan inflation lumen extend through the tubular body, and are in aside-by-side configuration. The main lumen is sized to receive atherapeutic and/or diagnostic device such as a balloon angioplastycatheter or an atherectomy catheter. The tubular body is provided with amanifold. The manifold has an aspiration port which is in fluidcommunication with the main lumen. The distal end of the tubular bodyalso has a tip formed of a more flexible material than that used to formthe tubular body.

[0008] In one preferred embodiment, an inflatable balloon is mounted onthe distal end of the tubular body. An inflation port is also providedon the manifold in this embodiment. The inflation port is in fluidcommunication with the inflation lumen. In this embodiment, theinflatable balloon is formed of a block copolymer ofstyrene-ethylene-butylenestyrene.

[0009] In another preferred embodiment, the metallic braid or coil isformed of a metal selected from the group consisting of 304, 316, or 400series stainless steel, nitinol, platinum, gold, Elgiloy™, orcombinations thereof. Where a metallic braid is used, it may optionallyhave a braid density at a first point on the tubular body that isgreater than the braid density of the metallic braid at a second pointon the tubular body by at least 20 picks per inch. Similarly, where ametallic coil is used, it may optionally have a coil density at a firstpoint on the tubular body that is greater than the coil density at asecond point on the tubular body.

[0010] In another aspect of the present invention, there is provided acatheter comprising an elongate flexible tubular body having a proximalend and a distal end. Alternatively, there may be provided a circularcross-sectional configuration at the proximal end which is continuouswith a distal end having a reduced internal and outer tubular bodydiameters. A first and second lumen extend through the tubular body fromthe proximal end to the distal end in a side-by-side configuration. Thefirst lumen has a generally circular cross-sectional configuration atthe proximal end and a generally oval cross-sectional configuration atthe distal end. The second lumen has a diameter no smaller than 0.05inches, preferably no smaller than 0.08 inches, and is adapted toslidably accommodate a therapeutic or diagnostic device.

[0011] In one preferred embodiment, an inflatable balloon is mounted onthe distal end of the tubular body. The inflatable balloon is in fluidcommunication with the first lumen, such that fluid passing through thefirst lumen may be used to inflate or deflate the inflatable balloon.The second lumen size may vary in certain embodiments, such that in oneembodiment, the second lumen has a diameter no smaller than about 0.05inches, and is preferably no less than 0.080 inches.

[0012] In another aspect of the present invention, there is provided acatheter with variable stiffness, comprising a tubular body having aproximal end and a distal end. A metallic braid or metallic coil iswithin the tubular body. In one embodiment, the proximal end of thetubular body has a lower braid or coil density than the distal end. Inanother embodiment, the braid or coil density is kept constant along thelength of the tubular body, and the tubular body is formed of materialswith greater stiffness at the proximal end. In another embodiment, acombination of braids and coils of varying density can be used atvarious points along the tubular body, to create a catheter tubular bodyhaving a more flexible distal end.

[0013] In another aspect of the present invention, there is provided amethod of making a catheter tubular body. The method comprises providinga first polymeric tube formed of a first material having a first meltingpoint. The first polymeric tube is then inserted into a second polymerictube to form a combined tube. The second polymeric tube is formed of asecond material having a second melting point which is less than thefirst melting point. The combined tube is then placed adjacent to athird tube. The third tube is formed in part of the second material. Thetubes are then heated to a temperature greater than the second meltingpoint but less than the first melting point, such that the combined tubemelt fuses with third tube to form a catheter tubular body having twolumen extending therethrough in a side-by-side configuration. The firstmaterial may be selected from the group comprising polyimide, polyamide,PET and PEEK, blends thereof and the second material may be selectedfrom the group comprising Pebax™, polyethylene, nylon, or Hytrel™ orblends thereof. Preferably, the temperature of the heating step is fromabout 250° to 600° F. It is also preferred that the third tubeincorporate a metallic member, such as a braid or coil.

[0014] In general, it is an objection of the present invention toprovide an apparatus or an assembly and method which can be used withapproved diagnostic and therapeutic devices while minimizing theopportunities for emboli to migrate downstream.

[0015] Another object of the present invention to provide an apparatusor assembly and method of the above character which makes it possible toperform therapeutic procedures without using perfusion.

[0016] Another object of the invention is to provide an apparatus orassembly and method of the above character in which the proximal balloonutilized is a balloon carried by a guide wire.

[0017] Another object of the invention is to provide an apparatus orassembly and method of the above characters in which the inflationfitting carried by the proximal extremity of the balloon-on-a-wire isremovable so that catheters can be slid over the wire without removal ofthe wire from the site in which it is disposed.

[0018] Another object of the present invention is to provide anapparatus or assembly and method for treating occluded vessels of theabove character which makes it possible to prevent downstream flow ofdebris or emboli.

[0019] Another object of the invention is to provide an apparatus andmethod which makes it possible to reverse the flow of blood in anoccluded vessel during the time that a stenosis is being crossed.

[0020] Another object of the invention is to provide an apparatus andmethod of the above character in which a negative pressure is createdwithin the vessel to reverse the flow of blood in the vessel.

[0021] Another object of the invention is to provide an apparatus andmethod of the above character in which it is only necessary to stop theflow of blood in a vessel of a patient for a very short period of time.

[0022] Another object of the invention is to provide an apparatus andmethod in which a working space is provided in the vessel free of bloodfor treatment of the stenosis.

[0023] Another object of the invention is to provide an apparatus andmethod of the above character in which material which is dislodgedduring the treatment of the occlusion or stenosis is removed by suction.

[0024] Another object of the invention is to provide an apparatus andmethod of the above character in which blood is shunted around theworking space.

[0025] Another object of the invention is to provide an apparatus andmethod in which a cutting device is utilized for treatment of thestenosis or atheroma in the vessel and in which the material removedfrom the stenosis or atheroma is aspirated out of the operating space.

[0026] Another object of the invention is to provide an apparatus andmethod of the above character in which the amount of material removedfrom the stenosis or atheroma can be precisely controlled.

[0027] Another object of the invention is to provide an apparatus andmethod of the above character which makes it possible to treat stenosesor occlusion in the vessel which are normally not accessible forsurgical procedures.

[0028] Another object of the invention is to provide an apparatus andmethod of the above character which utilizes two spaced apart balloonsto create the working space in the vessel.

[0029] Another object of the invention is to provide an apparatus andmethod of the above character that can be utilized to create a workingspace in a vessel having a bifurcation therein and in which the workingspace includes the bifurcation.

[0030] Another object of the invention is to provide an apparatus andmethod of the above character which utilizes three spaced apart balloonsto create the working space in the vessel having a bifurcation therein.

[0031] Another object of the invention is to provide an apparatus andmethod of the above character which includes a control console forcontrolling the inflation of the blood flow pump.

[0032] Another object of the invention is to provide an apparatus andmethod of the above character which is particularly adapted for use withthe carotid vessels.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is a side view of an embodiment of the catheter of thepresent invention.

[0034]FIG. 2 is a cross-sectional view of catheter of FIG. 1 along lines2-2.

[0035]FIG. 3 is a cross-sectional view of the catheter of FIG. 1 alonglines 3-3.

[0036]FIG. 4 is a longitudinal cross-sectional view of the distal end ofthe catheter of FIG. 1.

[0037]FIG. 5 is an enlargement of the region circumscribed by lines 5-5of the catheter of FIG. 4.

[0038]FIG. 6 is an illustration of the catheter of the present inventionas used in an emboli containment system.

[0039]FIG. 7 is a cross-sectional view of the emboli containment systemof FIG. 6 along lines 7-7.

[0040]FIG. 8 is a cross-sectional view of the emboli containment systemof FIG. 6 along lines 8-8.

[0041]FIG. 9 is a cross-sectional view of the emboli containment systemof FIG. 6 along lines 9-9.

[0042] FIGS. 10A-E illustrate the use of an embodiment of the catheterof the present invention in an emboli containment treatment procedure.

[0043]FIG. 11 is a side-elevational view partially in section showingthe catheter apparatus or assembly of the present invention for treatingoccluded vessels.

[0044]FIG. 12 is a cross-sectional view taken along the line 12-12 ofFIG. 11.

[0045]FIG. 13 is a cross-sectional view taken along the line 13-13 ofFIG. 11.

[0046]FIG. 14 is a cross-sectional view taken along the line 14-14 ofFIG. 11.

[0047]FIG. 15 is a schematic illustration of how the catheter apparatusshown in FIG. 11 is deployed in a carotid artery.

[0048] FIGS. 16A-16E are illustrations showing the various stepsutilized in deployment of the catheter apparatus in performing themethod of the present invention in a vessel where a bifurcation is notpresent.

[0049]FIG. 17 is a side-elevational view partially in section of anotherembodiment of a catheter apparatus or assembly incorporating the presentinvention for treating occluded vessels using an atherectomy device.

[0050]FIG. 18 is a cross-sectional view taken along the line 18-18 ofFIG. 17.

[0051]FIG. 19 is a cross-sectional view taken along the line 19-19 ofFIG. 17.

[0052]FIG. 20 is a side-elevational view in section of the distalextremity of another embodiment of a catheter apparatus incorporatingthe present invention and utilized for delivering an expandable stent toa stenosis.

[0053]FIG. 21A is a schematic illustration showing the manner in whichthe apparatus of the present invention is utilized in connection withvessels of a patient in performing the method of the present invention.

[0054]FIG. 21B is an additional partial schematic illustration showinginterconnections in the catheter apparatus shown in FIG. 21A.

[0055]FIG. 22 is a plan view of another embodiment of a catheterapparatus incorporating the present invention.

[0056]FIG. 23 is a cross-sectional view taken along the line 23-23 ofFIG. 22.

[0057]FIG. 24 is an end elevational view looking down the line 24-24 ofFIG. 22.

[0058]FIGS. 25A, B, C, and D are illustrations or cartoons showing themethod of the present invention being utilized with the apparatus shownin FIG. 21 in a vessel having a bifurcation therein.

[0059]FIG. 26 is a side-elevational view of a main catheterincorporating the present invention.

[0060]FIGS. 26A and 26B are partial side-elevational views of the distalextremities showing alternative embodiments of the main catheter of thepresent invention incorporating, respectively, Judkins left shape andJudkins right shape in their distal extremities.

[0061]FIG. 27 is a cross-sectional view taken along the line 27-27 ofFIG. 26.

[0062]FIG. 28 is a cross-sectional view taken along the line 28-28 ofFIG. 26.

[0063]FIG. 29 is an enlarged partial cross-sectional view of the distalextremity of the catheter shown in FIG. 26.

[0064]FIG. 30 is a side-elevational view of the balloon-on-a-wireconstruction incorporating the present invention.

[0065]FIG. 31 is a cross-sectional view taken along the line 31-31 ofFIG. 30.

[0066]FIG. 32 is an enlarged cross-sectional view of the distalextremity of the construction in FIG. 30.

[0067]FIG. 33 is a cross-sectional view similar to FIG. 32 but showing adifferent embodiment utilizing a twisted dual core.

[0068]FIG. 34 is a cross-sectional view similar to FIG. 32 but showingthe use of a twisted core.

[0069]FIG. 35 is a cross-sectional view of the proximal removablefitting of the construction shown in FIG. 30.

[0070]FIG. 36 is a side-elevational view partially in cross section ofan irrigation catheter incorporation the present invention.

[0071]FIGS. 36A and 36B are side-elevational views of the distalextremities of additional embodiments of irrigation cathetersincorporating the present invention.

[0072] FIGS. 37-43 are cartoons showing the manner in which theapparatus of the present invention shown in FIGS. 26-36 is usedperforming a therapeutic procedure in accordance with the presentinvention.

[0073]FIG. 44 is a side-elevational view partially in cross-section ofanother embodiment of a main catheter incorporating the presentinvention.

[0074]FIG. 45 is a side-elevational view partially in cross-sectionshowing another embodiment of an irrigation catheter incorporating thepresent invention.

[0075] FIGS. 46-50 are cartoons showing the manner in which atherapeutic carotid procedure is performed in accordance with thepresent invention where there is a bifurcation.

[0076]FIG. 51 is a side-elevational view partially in section of anotherembodiment of a balloon-on-a-wire incorporating the present invention.

[0077]FIG. 52 is a cross-sectional view taken along the line 52-52 ofFIG. 51.

[0078]FIG. 53 is a side-elevational view in section of anotherembodiment of a catheter apparatus incorporating the present inventionfor treating occluded vessels.

[0079]FIG. 54 is a side-elevational view in section similar to FIG. 53but showing the apparatus in FIG. 53 with the self-expandable sealingmeans deployed.

[0080]FIG. 55 is a side-elevational view in section of anotherembodiment of a catheter apparatus incorporating the present inventionfor treating occluded vessels.

[0081]FIG. 56 is a view similar to FIG. 55 but showing theself-expandable sealing means deployed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0082] Referring to FIG. 1, there is depicted an embodiment of theballoon catheter of the present invention. Although illustrated anddescribed below in the context of an emboli containment system featuringballoon dilatation treatment of a stenotic lesion, it is to beunderstood that the present invention can be easily adapted to a varietyof emboli containment treatment applications. For example, the presentinventors contemplate that the catheter of the present invention can beused in emboli containment treatment procedures which includeatherectomy, stent implantation, drug delivery, as well as otherapplications. Furthermore, although depicted and described as a twolumen catheter, it should be appreciated that the present invention mayalso be adapted to catheters having more than two lumen. The manner ofadapting the present invention to these various treatments andstructures will become readily apparent to those of skill in the art inview of the description which follows.

[0083] Catheter 10 generally comprises an elongate flexible tubular body16 extending between a proximal control end 12 and a distal functionalend 14. Tubular body 16 has a main lumen 30 which extends between ends12 and 14. Main lumen 30 terminates in a proximal opening 23 and adistal opening 27. A smaller inflation lumen 32, configured in aside-by-side relationship with main lumen 30, extends along the lengthof tubular body 16 and may terminate within or near an occlusion balloon26 mounted on the distal end 14 of catheter 10, as described below.Inflation lumen 32 is in fluid communication with balloon 26, such thatfluid passing through inflation lumen 32 may be used to inflate ordeflate balloon 26. In some embodiments, the inflation lumen mayoriginate at a point distal to the proximal end 12, and extend distallyfrom that point in a side-by-side configuration with main lumen 30.

[0084] In some embodiments, instead of an occlusion balloon 26, distalend 14 is provided with a mechanical occlusive device such as apull-wire activated braid which filters all particles larger than 12microns. Alternatively, other occlusive filtering devices may also beused, as is known by those of skill in the art.

[0085] A control manifold 19 is provided at the proximal end 12 ofcatheter 10. Control manifold 19 is generally provided with a number ofports to provide access to the catheter lumen. For example, for theembodiment depicted in FIG. 1, control manifold 19 is provided with acatheter end-access port 22 and a catheter side-access port 24, toprovide an introduction point for the insertion of other catheters intolumen 30. Ports 22 and 24 are preferably provided with standard TouhyBorst connectors, although other sealing type connectors, such as ahemostasis valve, may be used. Manifold 19 is also provided with anaspiration port 20 which is in fluid communication with lumen 30, forattachment of devices to aspirate fluid into opening 27, through lumen30, and out port 20. An inflation port 18, in fluid communication withlumen 32, is further provided on manifold 18 for attachment of devicesto inflate or deflate balloon 26. In one preferred embodiment, ports 18and 20 are provided with standard luer connectors, to facilitateattachment of standard inflation or aspiration apparatus, respectively,to ports 18 and 20. Other embodiments of catheter 10 may feature more orless ports, depending upon the number of lumen in the catheter and thedesired functionalities of the catheter.

[0086] Manifold 19 is preferably formed out of hard polymers or metals,which possess the requisite structural integrity to provide a functionalaccess port to the catheter lumen, such as for balloon inflation orfluid aspiration. In one preferred embodiment, manifold 19 is integrallyformed out of medical grade polycarbonate. Other suitable materials maybe used to form manifold 19, such as polyvinyl chloride, acrylics,acrylonitrile butadiene styrene (ABS), nylon, and the like.

[0087] Manifold 19 is attached to tubular body 16 so that the variousports are placed in communication with the appropriate lumen, asdescribed above in connection with FIG. 1. Preferably, a strainrelieving connector 11 is used to join manifold 19 to tubular body 16.For the embodiment depicted in FIG. 1, strain relieving connector 11consists of a length of flexible polymeric tubing, such as 40 durometer(D) Pebax™, or other polyether block amides, and other similarmaterials. Tubular body 16 is inserted in one end of strain relievingconnector 11, and the other end of strain relieving connector 11 isinserted into manifold 19. Suitable adhesives, such as a cyanoacrylate,epoxies, or uv curable adhesives, may be used to bond manifold 19 tostrain relieving connector 11. Alternately, manifold 19 may also beinsert molded with the tubular body 16, as is known by those of skill inthe art. Adhesives may also be used to bond the strain relievingconnector 11 to tubular body 16, or alternately, conventional heatbonding, as known to those of skill in the art, may be used to attachtubular body 16 to strain relieving connector 11.

[0088] The length of tubular body 16 may be varied considerablydepending upon the desired application. For example, where catheter 10is to be used as part of an emboli containment system for treatment ofcarotid artery disease, with catheter 10 being introduced at the groin,the length of tubular body 16 may range from 80 to 110 centimeters, andis preferably 95 cm. Other treatment procedures, requiring a longer orshorter tubular body 16, are easily accommodated by the presentinvention, by forming a tubular body 16 of the desired length during themanufacturing process.

[0089] The outer diameter of tubular body 16 may also be variedconsiderably, and in most cases, will depend upon the intended treatmentprocedure for which catheter 10 will be used. That is, the outerdiameter of tubular body 16 must be large enough to be capable offorming a main lumen 30 which can slidably accommodate the othercatheters used in the emboli containment system, as described in detailbelow. However, the outer diameter of tubular body 16 must also besmaller than the internal diameter of smallest blood vessel throughwhich catheter 10 passes during the selected treatment procedure. Ingeneral, the diameter of main lumen 30 may range from at least about0.05 inches to about 0.12 inches, and be capable of accommodating manytypes of catheters to be used therein, while still maintaining a lowprofile for the diameter of tubular body 16.

[0090] For many treatment applications, it has been found that a tubularbody having an outside diameter of no more than about 0.135 inches (10French) is preferred. Advantageously, with an outer diameter of thissize, main lumen 30 may have an internal diameter of about 0.10 inches,making lumen 30 capable of accommodating a wide variety of treatmentcatheters, or catheters used for diagnostic purposes. Of course, as willbe appreciated by those of skill in the art, where the cathetersintended to be inserted into lumen 30 are known to have outer diameterssignificantly smaller than 0.10 inches, such that lumen 30 may besmaller than 0.10 inches and still accommodate them, a tubular body 16having an outer diameter of less than 0.135 inches may be selected.

[0091] Although not required, the interior surface of lumen 30 may beprovided with a liner 35 formed of a lubricous material, to reduce thefrictional forces between the lumen surface and the catheters which areinserted into lumen 30. In one preferred embodiment, liner 35 is formedout of polytetrafluoroethylene (PTFE). Lubricous materials other thanPTFE, which are biocompatible, fairly flexible, and easily mounted toother polymeric materials of the type used to form catheter tubularbodies, may also be used to form liner 35. Examples of such materialsinclude polyethylene, Pebax™, nylon, and the like. Where increasedflexibility of the distal end 14 of catheter 10 is desired, Pebax™ maybe used in place of PTFE along a selected portion of distal end 14, suchas the distal most 15-20 cm of end 14.

[0092] To minimize the outer diameter of tubular body 16, it ispreferable that inflation lumen 32 be as small as possible in accordancewith its function. That is, inflation lumen 32 is preferably no largerthan required to provide sufficient fluid to balloon 26 for rapidinflation, or so that fluid may be quickly withdrawn from balloon 26during deflation. For compliant expansion balloons of the type describedbelow, inflation lumen diameters of from about 0.008 inches to about0.018 inches are satisfactory, with a diameter of about 0.014 inchesbeing preferred for some applications.

[0093] Furthermore, in one embodiment, as illustrated in FIGS. 1-3, theouter diameter of tubular body 16 just proximal to balloon 26 isminimized by providing an inflation lumen 32 a with an ovalcross-sectional configuration, as illustrated in FIG. 3. Preferably,inflation lumen 32 a has an oval cross-sectional configuration whichextends proximally from the proximal edge balloon 26 by a distance of atleast 0.1 cm, more preferably 1 cm, and optimally by a distance equal tothe length of tubular body 16. For ease of manufacturing, thecross-sectional configuration of lumen 32 at points further proximal toballoon 26 may be generally circular, as illustrated in FIG. 2. Wherethe lumen configuration differs from proximal to distal end, asillustrated in FIGS. 2 and 3, a region of transition 33 is providedwherein the lumen configuration changes from circular to oval.

[0094] It will be appreciated by those of skill in the art that othercross-sectional configurations of lumen 32 a may be provided and stillfunction to reduce the profile of tubular body 16. For example,triangular, rectangular, or other non-oval cross sectionalconfigurations are easily adapted to lumen 32 a, and the manner ofincorporating such alternative cross-sectional configurations will bereadily apparent to those of skill in the art in view of the descriptionwhich follows.

[0095] A variety of different manufacturing methods may be used to alterthe cross-sectional configuration of lumen 32, as will be appreciated bythose of skill in the art. In one preferred method, lumen 32 is formedof a polymeric tube, such as a polyimide tube, which has been compressedat one end so that it has the desired oval shape. The polyimide tube isthen inserted into a second tube formed of a material having a lowermelting point than polyimide, such as 72D Pebax™. The combination isthen heat bonded to another tube defining main lumen 30, such as abraided Pebax™ tube, as described below. The heat bonding takes place ata temperature greater than the melting temperature of Pebax™, but lessthan the melting temperature of polyimide, so that the Pebax™ tubes meltfuse to form the two lumen tubular body.

[0096] Alternately, the cross-sectional configuration, as well as thecross-sectional area of lumen 32, may also be altered by joining twoseparate polymeric tubes together to form a continuous inflation lumen32. One of the tubes, corresponding to the proximal end of catheter 10as shown in FIG. 3, may have a circular cross-sectional configuration.The second tube, corresponding to the distal end of catheter 10 as shownin FIG. 2, has an oval configuration. One end of a mandrel may beinserted into each of the tubes, and conventional heat bonding may beused to create the cross-sectional configuration transition. As before,the combined tube may then be heat bonded to a second tube defining mainlumen 30 to form tubular body 16.

[0097] As illustrated in FIG. 1, an inflatable balloon 26 is mounted onthe distal end 14 of catheter 10. In most applications where catheter 10is to be used in an emboli containment treatment procedure, inflatableballoon 26 will function as an occlusion balloon, to prevent blood frompassing through the blood vessel distal of balloon 26. Thus, inflatableballoon 26 is preferably able to expand to fit a variety of differentblood vessel diameters. Accordingly, it is preferred that inflatableballoon 26 have a compliant expansion profile, tending to increase inradial diameter with increasing inflation pressure. To achieve this,balloon 26 may be made out of materials which impart such expansioncharacteristics, including elastomeric materials such as latex orsilicone. In one preferred embodiment, inflatable balloon 26 is formedout of a material comprising a block copolymer ofstyrene-ethylene-butylene-styrene, sold under the trade name C-Flex™.Further details as to balloons of this type are disclosed in ourcopending application entitled PRE-STRETCHED CATHETER BALLOON, Ser. No.08/812,139, filed Mar. 6, 1997, now abandoned, the entirety of which isincorporated by reference.

[0098] Inflatable balloon 26 may be placed in fluid communication withlumen 32 a via a fill hole (not shown) extending through tubular body 16within balloon 26, such that fluid may be introduced into lumen 32through inflation port 18 to inflate balloon 26. Alternately, lumen 32 amay terminate within balloon 26, to provide the requisite fluidcommunication. Balloon 26 may be attached to tubular body 16 by anysuitable manner known to those of skill in the art, such as adhesives orheat bonding.

[0099] Tubular body 16 must have sufficient structural integrity, or“stiffness,” to permit catheter 10 to be advanced through vasculature todistal arterial locations without buckling or undesirable bending oftubular body 16. However, it is also desirable for tubular body 16 to befairly flexible near distal end 14, so that tubular body 16 may benavigated through tortuous blood vessel networks. Thus, in one preferredembodiment, tubular body 16 is made to have variable stiffness along itslength, with the proximal portion of tubular body 16 being less flexiblethan the distal portion of tubular body 16. Advantageously, a tubularbody 16 of this construction enables a clinician to more easily inserttubular body 16 into blood vessel networks difficult to reach by atubular bodies having uniform stiffness. This is because the stifferproximal portion provides the requisite structural integrity needed toadvance tubular body 16 without buckling, while the more flexible distalregion is more easily advanced into and through tortuous blood vesselpassageways.

[0100] In one preferred embodiment, variable stiffness along the lengthof tubular body 16 is achieved by forming a polymeric tubular body 16which incorporates along its length a variable stiffness metallicmember. The metallic member may comprise a braid or coil, and may havevarying braid density or coil pitch at different points along thecatheter tubular body. For example, as shown in FIGS. 2 and 3, tubularbody 16 may be provided with a braid 36 incorporated into the wallstructure of tubular body 16. Referring to FIG. 1, to achieve variablestiffness, proximal region A of catheter 10 is provided with a metallicbraid 36 having a lower braid density than that present in the metallicbraid 36 a of distal region B. The lower braid density of proximalregion A permits polymer flow in between the braids during the formationof the tubular body. Because the polymer is relatively stiffer than thebraid, the lower braid density results in proximal region A being lessflexible, or “stiffer”, than distal region B. In one preferredembodiment, the braid density of proximal region A varies from 60 to 80picks per inch, while that of region B varies from 90 to 110 picks perinch.

[0101] As will be appreciated by those of skill in the art, metallicmembers other than braids may be incorporated into tubular body 16 tocreate variable stiffness. For example, a metallic coil may beintroduced into tubular body 16. The coil may have different pitch alongthe length of tubular body 16, such that region A is provided with acoil having a lower pitch than that present in region B. The manner ofadapting a coil, and other metallic members, to the catheter tubularbody in place of a braid will become readily apparent to those of skillin the art in view of the description which follows.

[0102] The precise density of the braiding provided to regions A and Bcan be varied considerably at the point of manufacture, such thatcatheters having a variety of different flexibility profiles may becreated. Moreover, the braid density may be varied within catheterregions A and B as well, by providing a metallic braid which has a braiddensity gradient along its length. For example, the most proximal partof region A may be provided with a metallic braid 36 having a braiddensity of about 60 picks per inch, with the braid density increasingdistally at a certain rate so that the final pick count is not more than110 picks per inch at the distal end.

[0103] A variety of different metals, known to be ductile and shapeableinto fine wires and flat ribbons, having a diameter of about 0.0005inches to about 0.005 inches for wires, or the same thickness for aribbon, may be used to form the metallic braids 36 and 36 a or metalliccoils. For example, stainless steel, platinum, gold and nitinol, orcombinations thereof are all suitable metals. In one preferredembodiment, braid 36 is formed of stainless steel, and has a braiddensity which varies from 70 picks per inch at the most proximal part ofregion A, to 100 picks per inch at the most distal part of region B.

[0104] Metallic braids 36 may be introduced into the structure oftubular body 16 through conventional catheter forming techniques. Forexample, tubular body 16 may be formed by braiding over a 72D Pebax™tube that has a removable core mandrel in the internal diametersupporting the Pebax™ tube, and then inserting the braided tube into a72D Pebax™ outer tube at the proximal region A and a 35D Pebax™ tube atthe distal region B, so that the braid is sandwiched between the innerand outer tubes. A stainless steel support mandrel may be inserted intothe removable core mandrel as additional support. A shaping containersuch as a fluorinated ethylene propylene (FEP) shrink tube is insertedover the outer Pebax™ tube, and the entire apparatus may then be placedin a hot box or oven kept at a temperature slightly greater than themelting temperature of the Pebax™ tubes. The Pebax™ tubes will melt andfuse together, and once cooled, will form a tubular body incorporatingthe metallic braid. The shaping container and mandrels may then beremoved and discarded.

[0105] In another embodiment, variable stiffness of tubular body 16 maybe achieved by forming regions A and B of tubular body 16 out ofpolymeric materials having differing degrees of stiffness. For example,one half of an inner tube of 72D Pebax™ may be inserted into an outertube of 35D Pebax™, and the other half of the inner tube may be insertedinto a 72D Pebax™ outer tube. The combination may then be heat fused, asdescribed above. The 35D/72D Pebax™ combination forms a more flexibletubular body than the region 72D/72D Pebax combination. More or lessflexible materials may be used as desired to alter the flexibility ofthe resulting tubular body. Furthermore, the flexibility of the variousregions of a tubular body formed in this manner may be varied further byincorporating a metallic member having either a uniform density, or avarying density, into the tubular body, as described above.

[0106] In another preferred embodiment, variable stiffness along thelength of the tubular body may be achieved by using different metallicmembers in regions A and B. For example, proximal region A may beprovided with a multilayer coil, while distal region B may be providedwith a braid. Alternately, proximal region A may be provided with ametallic braid, while distal region B may be provided with a singlelayer coil. As discussed above, the densities of the metallic members inthe respective sections may be varied considerably to select for adesired variable stiffness profile, as will be appreciated by those ofskill in the art.

[0107] In one preferred embodiment, variable stiffness along the lengthof the tubular body is achieved by keeping the braid density constantalong the length of tubular body 16 and then forming the proximal anddistal portions of tubular body 16 of polymeric materials of differingstiffness. For example, braid density may be uniform and range from60-80 picks/inch, more preferably be about 70 picks/inch, with region Abeing formed of 72D Pebax™ and region B being formed of 25-50D Pebax™.Alternately, region A can be formed of high density polyethylene andregion B of low density polyethylene.

[0108] Moreover, any of a variety of different polymeric materials knownby those of skill in the art to be suitable for catheter bodymanufacture may be used to form tubular body 16. For example, tubularbody 16 may be formed out of Pebax™, blends of Pebax™, and nylons,polyetheretherketone (PEEK), polyethylenes, and Hytrel™, and the like.Different materials might also be combined or blended to select fordesirable flexibility properties.

[0109] Also, although tubular body 16 has been described in the contextof having two regions of differing flexibility, it will be readilyappreciated by those of skill in the art that three or more regions ofdiffering flexibility may easily be provided, by adapting the teachingscontained herein.

[0110] In the above-discussed embodiments, and all other embodiments ofthe present invention, it may be preferred to provide main lumen 30 andthe outer surface of tubular body 16 with a hydrophillic coating, ahydrophobic coating, or combinations thereof. For example, main lumen 30may be provided with a hydrophobic coating, such as silicone, whiletubular body 16 is provided with a hydrophillic coating, such aspolyvinyl pyrrolidone (PVP), polyurethane blends, copolymers ofacrylonitrile, and the like. Other hydrophobic and hydrophilliccoatings, as known to those of skill in the art, may also be used. Inaddition, any of a variety of antithrombogenic coatings, such asheparin, may also be applied to the catheter of the present invention,alone or in combination with other coating types.

[0111] Referring to FIGS. 4 and 5, there is illustrated across-sectional view of the distal end 14 of catheter 10. Distal end 14is provided with a soft distal tip 50, which is not preformed withtubular body 16, but is instead attached to tubular body 16 as a tubepost manufacturing step. Distal tip 50 is preferably soft enough andflexible enough, so as to minimize trauma to body vessels as catheter 10is advanced, and also to facilitate navigation of catheter 10 intortuous vessels. In one preferred embodiment, distal tip 50 is formedas a 0.5 cm sleeve of 25-40D Pebax™, and is bonded to tubular body 16 byheat fusing. Alternately, distal tip 50 may be attached to tubular body16 by adhesives, or by insert molding, as is known to those of skill inthe art. Preferably, distal tip 50 is in alignment with tubular body 16,and does not bend or curve, such that the radial axis of distal tip 50is substantially the same as that of tubular body 16.

[0112] The distal end 14 of catheter 10 is also preferably provided witha radiopaque material 44. Advantageously, radiopaque material 44 servesas a marker to help the clinician position catheter 10 during a medicalprocedure. Various well-known radiopaque materials may be used in distalend 14, such as platinum, gold, and platinum-iridium blends. The fulllength, or part of the length of the tubular body, may also beradiopaque by blending radiopaque materials in the polymeric materialsused to form the body. Furthermore, radiopacity of the tip can also beachieved by loading (i.e., comparing) the distal tip 50 with asufficient amount of barium sulfate. Alternatively, bismuthsubcarbonate, bismuth trioxide or bismuth oxychloride may be used as aradiopaque filler. Also, radiopacity may be achieved by using radiopaquewire or flat ribbon to make the braid or coil.

[0113] Illustrated in FIGS. 6-9, there is an emboli containment systemutilizing catheter 10 of the present invention. Catheter 10 of thepresent invention is used in the treatment of a stenosis 55 in a lumen50 in a blood-carrying vessel 58 in which the stenosis 55 at leastpartially occludes the lumen 50. The emboli containment system depictedin FIG. 6 comprises a catheter 10, as described above, as well ascatheters 100 and 200.

[0114] Catheter 100 comprises an elongate flexible tubular body 116having proximal end and distal end 114. An inflatable balloon 126 of thesame type as inflatable balloon 26 is coaxially mounted on tubular body116 on the end 114 of catheter 100. The tubular body 116 has centrallydisposed inflation lumen 132 in fluid communication with balloon 126,such that fluid passing through lumen 132 may be used to inflate balloon126. Alternatively, fluid may be withdrawn from lumen 132 to deflateballoon 126. As shown in FIG. 6, catheter 100 is disposed within mainlumen 30 of catheter 10 and is slidably and coaxially mounted thereinfor variable displacement of balloon 126 with respect to the firstballoon 26, as hereinafter described. One preferred embodiment of acatheter 100 is disclosed in our co-pending application, entitled HOLLOWMEDICAL WIRES AND METHODS OF CONSTRUCTING SAME, Ser. No. 08/812,876,filed Mar. 6, 1997, now U.S. Pat. No. 6,068,623, the entirety of whichis incorporated by reference.

[0115] The emboli containment system also comprises catheter 200comprising an elongate flexible tubular body 216 having proximal end anddistal end 214. Catheter 200 is also provided with a generally centrallydisposed lumen 230 extending from the proximal end to the distal end ofcatheter 200, and through which catheter 100 is coaxially and slidablymounted.

[0116] The distal end 214 of catheter 200 is provided with means forperforming a medical procedure, such as an apparatus for treatingstenotic lesion 55. In the embodiment of the invention shown in FIG. 6,this means comprises a dilatation balloon 226, which is preferably anon-compliant inflatable balloon which is coaxially mounted on thedistal end 214 of catheter 200. Balloon 226 may also be attached totubular body 216 in the same manner as balloons 26 and 126 hereinbeforedescribed. Tubular body 216 is provided with a balloon inflation lumen232 which is in fluid communication with balloon 226, such that balloon226 may be inflated by the passage of fluid through lumen 232.

[0117] The operation and use of the emboli containment system utilizingthe catheter of the present invention for treating occluded vessels maynow be briefly described in connection with an occlusion formed by astenosis in a carotid artery, as illustrated in FIGS. 10A-E.

[0118] Catheter 100 is inserted into an incision into a femoral arteryof a patient and is advanced through that artery into the aorta of thepatient and into the ostium of the carotid artery to be treated. Aftercatheter 100 has been introduced, catheters 10 and 200, with balloons 26and 226 completely deflated, are introduced over catheter 100 and areadvanced into the ostium of the carotid artery and into the lumen orpassageway of the vessel as shown in FIGS. 10A-E.

[0119] The emboli containment system is advanced until catheter 10 isproximal of a stenosis 55 in the vessel lumen 50 to be treated. Balloon26 is then inflated by introducing a suitable inflation medium such as aradiopaque liquid into port 18 to cause it to pass through the ballooninflation lumen 32 to inflate balloon 26, as shown in FIG. 10B. Balloon26 is progressively inflated until it engages the side wall 58 of thevessel to occlude the lumen 50.

[0120] Catheter 100 is then advanced through stenosis 55 as shown inFIG. 10C. Catheter 100 with deflated balloon 126 thereon is advancedthrough stenosis 55 until the balloon 26 is distal of stenosis 55 asshown in FIG. 10D. Balloon 126 is then inflated by passing an inflationmedium through lumen 132 to the interior of the balloon 126 to inflatethe balloon 126 until it engages the sidewall 58 of the vessel lumen 50.As soon as the balloon 126 has been inflated, a working space isprovided between balloons 26 and 126, so that medical procedures can beundertaken to remove or reduce the stenosis 55 in the space betweensecond balloons 26 and 126, without risk of unwanted particles or emboliescaping into the blood stream.

[0121] For emboli containment systems featuring balloon dilatationtreatment, it is desired to compress the plaque or material forming thestenosis to provide a larger vessel. Thus, catheter 200 is advanced overcatheter 100 to cause distal end 214 with balloon 226 thereon to beadvanced into the working space. As soon as balloon 226 has beenproperly positioned within stenosis 55, balloon 226 is inflated with asuitable inflation medium, as for example a radiopaque liquid. Balloon226 can be inflated to the desired pressure to cause compression of theplaque of the stenosis 55 against the sidewall 58 of lumen 50 by theapplication of appropriate inflation pressure. As in conventionalangioplasty procedures, balloon 226 can be formed of a non-elasticrelatively non-compliant material so that appropriate pressures, such as10-15 atmospheres, can be used within balloon 226 to apply compressiveforces to the vessel without danger of rupturing the vessel. It shouldbe appreciated that the non-elastic capabilities can also be achieved bya composite elastic material.

[0122] Once the clinician is satisfied that the occlusion formingstenosis 55 has been sufficiently compressed, balloon 226 can bedeflated. After the appropriate dilation of stenosis 55 has beenaccomplished, catheter 200 can be removed from the stenosis. Moreover,in one preferred method, catheter 200 is completely withdrawn from theemboli containment system, and an irrigation catheter is inserted overcatheter 100 and through lumen 30, as described in our copendingapplication entitled METHOD FOR EMBOLI CONTAINMENT, Ser. No. 08/812,875,filed Mar. 6, 1997, now U.S. Pat. No. 5,833,644, the entirety of whichis incorporated by reference. Fluid introduced into the working spacemay be removed by supplying a negative pressure or suction to aspirationport 20. This creates a negative pressure within space 30 a defined bythe interior surface of lumen 30 and outer tubular body 216, to suck oraspirate blood or other fluids in lumen 50 into space 30 a and out ofaspiration port 20. In this manner, irrigation and aspiration of theworking space may take place so that any plaque coming off the occlusionforming the stenosis 55 can be aspirated out of the vessel.Subsequently, balloon 26 and balloon 126 can be deflated to permitnormal blood flow through the vessel lumen 50. The entire catheterassembly can then be removed and a suture applied to the incisioncreated to obtain access to the femoral artery.

[0123] In general, the catheter apparatus is for treatment of a stenosisin a lumen in a blood carrying vessel. It is comprised of a maincatheter and a balloon-on-a-wire device. The main catheter is comprisedof a first flexible elongate tubular member having proximal and distalextremities. A first inflatable elastic balloon having an interior iscoaxially mounted on the distal extremity of the first flexible elongatetubular member. The first flexible elongate tubular member has a ballooninflation lumen therein in communication with the interior of the firstballoon. The first elongate tubular member has a main lumen thereinextending from the proximal extremity to the distal extremity andexiting through the distal extremity. An adapter is mounted on theproximal extremity of the first flexible elongate tubular member and hasa balloon inflation port in communication with the balloon inflationlumen, a therapeutic catheter port and an aspiration port incommunication with the main lumen. The balloon-on-a-wire device iscomprised of a guide wire having proximal and distal extremities.

[0124] A second inflatable elastic balloon has an interior and iscoaxially mounted on the distal extremity of the guide wire. The guidewire has a balloon inflation lumen therein in communication with theinterior of the second balloon. The balloon-on-a-wire device is slidablymounted in the therapeutic catheter port and in the main lumen of thefirst elongate tubular member with the proximal extremity of the guidewire being disposed outside of the main lumen. Removable valve means iscarried by the proximal extremity of the guide wire and has thecapability of forming a fluid-tight seal with respect to the guide wirewhile permitting relative axial movement of the guide wire and the firstflexible elongate tubular member with respect to each other whereby thefirst balloon can be moved so that it is proximal of the stenosis andthe second balloon so that it is distal of the stenosis. The removablevalve means includes an inflation port in communication with the ballooninflation lumen and the guide wire. The apparatus is also comprised ofmeans coupled to the balloon inflation port of the first flexibleelongate tubular member for inflating the first balloon and meanscoupled to the balloon inflation port of the removable valve means forinflating the second balloon to create a working space which bracketsthe stenosis.

[0125] More particularly as shown in FIGS. 11-14, the catheter apparatus311 of the present invention is for use in the treatment of a stenosis312 in a lumen 313 in a blood-carrying vessel 314 in which the stenosis312 has a length and a width or thickness which at least partiallyoccludes the lumen 313. The apparatus consists of a first elongateflexible tubular member 316 formed of a suitable plastic material whichis provided with proximal and distal extremities 317 and 318. A firstballoon 319 is mounted on the distal extremity 318 and preferably is acompliant balloon formed of a suitable elastic material such as a latexor a very low radiation polyethylene so that it can be inflated to thesize of the vessel 314 in which it is to be disposed. Thus, the balloon319 should be capable of expanding to various diameters depending on thesize of the vessel. The first balloon 319 can be formed as a separateballoon separate from the elongate tubular member 316 as shown andadhered thereto by suitable means such as an adhesive (not shown), or itcan be formed integral with the tubular member 16 in a manner well knownto those skilled in the art.

[0126] The tubular member 316 is provided with a large centrallydisposed or main lumen 321 extending from the proximal extremity 317 tothe distal extremity 318. It is also provided with a balloon inflationlumen 322 which has a distal extremity in communication with theinterior of the first balloon 319 through a port 323. The proximalextremity of the balloon inflation lumen 322 is in communication with aballoon inflation fitting 324 mounted on the proximal extremity 317 ofthe tubular member 316. The fitting 324 can be of a conventional type asfor example a Luer-type fitting which is adapted to be connected to aballoon inflation device (not shown) for inflating and deflating thefirst balloon 319.

[0127] The first tubular member 316 is also provided with an aspirationlumen 326 which exits through the distal extremity 318 and the proximalextremity 317 of the tubular member 316. A Luer-type fitting 327 ismounted on the proximal extremity 317 and is in communication with theaspiration lumen 326. The fitting 327 is adapted to be connected to asuitable aspiration or suction source (not shown) of a conventional typesuch as a syringe or rubber bulb for aspiration purposes as hereinafterdescribed.

[0128] The catheter assembly or apparatus 311 also consists of a secondelongate flexible tubular member 331 having proximal and distalextremities 332 and 333. A second inflatable balloon 336 of the sametype as the first inflatable balloon is coaxially mounted on the distalextremity 333 in a conventional manner. The tubular member 331 isprovided with a large generally centrally disposed arterial blood flowlumen 337 which opens through the distal extremity 333 and is incommunication with a Luer-type fitting 338 which as hereinafterdescribed is adapted to be connected to a supply of arterial blood fromthe patient which for example can be taken from another femoral arteryof the patient by the use of a blood pump.

[0129] The second tubular member 331 is also provided with a ballooninflation lumen 339 which is in communication with the interior of thesecond inflatable balloon 336 through a port 341. The proximal extremityof the lumen 339 is in communication with the Luer-type fitting 342mounted on the proximal extremity 332 of the second tubular member 31and as with the balloon inflation fitting 324 is adapted to be connectedto a balloon inflation-deflation device (not shown) of a conventionaltype. The second tubular member 331 is also provided with a lumen 343which also can be used as a guide wire and/or for introducing a salinesolution extending from the proximal extremity to the distal extremity.The lumen 343 is sized so that it is adapted to receive a conventionalguide wire 346 as for example a 0.014″ or 0.018″ guide wire and extendsfrom the proximal extremity to the distal extremity so that the guidewire 346 can extend beyond the distal extremity of the second tubularmember 331. A fitting 347 is provided on the proximal extremity 332 incommunication with the lumen 343 for introducing the saline solution.

[0130] As shown in FIG. 11, the second tubular member 331 is disposedwithin the central lumen 321 of the first tubular member 316 and isslidably and coaxially mounted therein for displacement of the secondballoon 336 with respect to the first balloon 319 as hereinafterdescribed.

[0131] The catheter assembly or apparatus 311 also consists of a thirdelongate flexible tubular member 351 having proximal and distalextremities 352 and 353. It is provided with a centrally disposed lumen356 extending from the proximal extremity 352 to the distal extremity353 and through which the second tubular member 331 is coaxially andslidably mounted.

[0132] Means 357 is provided on the distal extremity 353 of the thirdtubular member 351 for performing a medical procedure. In the embodimentof the invention shown in FIG. 11, this means 357 consists of a thirdballoon 358 which can be non-compliant coaxially mounted on the distalextremity of the third tubular member 351. The third balloon 358 can beattached in the same manner as the first and second balloons 319 and 336hereinbefore described. The third tubular member 351 is provided with aballoon inflation lumen 359 which has its distal extremity incommunication with the interior of the balloon 358 through a port 361.The proximal extremity of the balloon inflation 359 is in communicationwith a Luer-type fitting 362 provided on the proximal extremity 352 andadapted to be connected to a conventional inflation deflation device(not shown) for inflating and deflating the third balloon 358.

[0133] The operation and use of the catheter assembly or apparatus 311in the method of the present invention for treating occluded vessels maynow be briefly described in connection with an occlusion formed by astenosis in a vessel not having a bifurcation therein as for example insaphenous graft or in one of the right and left carotid arteries, alsocalled internal and external carotid arteries, of a patient inconnection with the illustrations shown in FIGS. 15 and 16A-16E. Aguiding catheter 363 (FIG. 15) of a conventional type is inserted intoan incision into a femoral artery 364 of a patient and is advancedthrough that artery into the aorta of the heart 365 of the patient andinto the ostium 366 of the selected carotid artery or vessel as forexample the left carotid 367.

[0134] After the guiding catheter has been appropriately positioned, theguide wire 346 is introduced separately into the guiding catheter oralong with the catheter assembly 311. The distal extremity of thecatheter apparatus or assembly 311 with all of the first, second andthird balloons 319, 336 and 358 completely deflated, is introduced intothe guiding catheter 363 along with or over the guide wire 346 and isadvanced through the guiding catheter 363 into the ostium 366 of thecarotid artery or vessel 367 and into the lumen or passageway 368 of thevessel as shown in FIGS. 15 and 16B.

[0135] The distal extremity of the catheter assembly 311 is advanceduntil it is just proximal of a stenosis 369 in the carotid artery 367 tobe treated. The balloon 319 is then inflated by introducing a suitableinflation medium such as a radiopaque liquid into the fitting 324 tocause it to pass through the balloon inflation lumen 322 through theport 323 and into the interior of the first balloon 319 to inflate thesame as shown in FIG. 16B. The balloon 319 is progressively inflateduntil it engages the side wall of the vessel 367 to occlude the vessel367. At the time that this is occurring, a negative pressure or suctionis applied to the aspiration fitting 327 to supply a negative pressurethrough the balloon inflation lumen 322 to suck or aspirate blood in thevessel 367 distal of the first balloon 319 into the aspiration lumen 326and out the aspiration fitting 327 to thereby reverse the flow of bloodthrough the stenosis as shown by the arrows 371 in FIG. 16B.

[0136] While a reverse flow of blood is occurring in the vessel 367, theguide wire 346 is advanced through the stenosis 369 as shown in FIG.16C. In the event that any pieces or particles of plaque are knocked offof the occlusion formed by the stenosis 369 by movement of the guidewire 346 through the same, such pieces of plaque or emboli will be drawnout with the reverse flow of blood into the aspiration lumen 326 and outof the aspiration fitting 327. During the time that the guide wire 346is being advanced through the stenosis 369 it may be desirable at thesame time to introduce a saline solution through the guide wire lumen343 of the second elongate flexible tubular member 331 to exit throughthe distal extremity of the second elongate flexible tubular member 331into the space immediately proximal of the stenosis 369. This introducedsaline solution aids the flow of particulate or other particlesdislodged from the stenosis 369 during advancement of the guide wire 346through the same and carries them back with the mixed saline bloodsolution through the aspiration lumen 326 in a manner hereinbeforedescribed.

[0137] With the guide wire 346 remaining in position, the secondelongate flexible tubular member 331 with the second balloon 336 thereonin a deflated condition is advanced over the guide wire 346 through thestenosis 369 until the second balloon 336 is distal of the stenosis 369as shown in FIG. 16D after which the second balloon 336 is inflated byintroducing an inflation medium as for example a radiopaque liquidthrough the inflation fitting 342 into the lumen 339 through the port341 to the interior of the second balloon 336 to inflate the secondballoon 336 until it engages the sidewall of the vessel 367.

[0138] Prior to, during or after inflation of the second balloon 336,the guide wire 346 can be removed. However, it is preferable to removethe guide wire 346 as soon as the second balloon 336 has been advancedso that it is beyond the stenosis 369. At this time, and certainly priorto complete inflation of the second balloon 336, blood is shunted acrossthe stenosis 369 and into the lumen 368 distal of the second balloon 336by introducing blood through the fitting 338 and into the centrallydisposed blood flow lumen 337 in the second tubular member 331 so thatit exits out the central lumen 337 distal of the second balloon 336. Theblood which is supplied to the fitting 337 can be taken from anotherfemoral artery of the patient and pumped into the fitting 338. Inaddition, if desired, the blood which is aspirated in the space distalof the first balloon 319 can be appropriately filtered and also suppliedto the fitting 338. By shunting blood past the stenosis 369 in thismanner it can be seen that blood is being continuously supplied to thecarotid artery of the patient during the time that the second balloon336 is inflated and occludes the lumen 368 in the vessel 367.

[0139] As soon as the second balloon 336 has been inflated, it can beseen that there is provided a working space 376 (FIG. 16D) between thefirst and second balloons 319 and 336 so that medical procedures can beundertaken to remove or reduce the stenosis 369 in the space between thefirst and second balloons 319 and 336.

[0140] Assuming that it is desired to compress the plaque or materialforming the stenosis 369 to provide a larger lumen, opening orpassageway through the stenosis 369 the third tubular member 51 can beadvanced by grasping the proximal extremity 352 to cause the distalextremity with the third balloon 358 thereon to be advanced into theworking space 376. As soon as the balloon 358 has been properlypositioned within the stenosis 369, the balloon 358 also can be inflatedwith a suitable inflation medium as for example a radiopaque liquid. Theballoon 358 can be inflated to the desired pressure to cause compressionof the plaque of the occlusion against the sidewall of the vessel 367 bythe application of appropriate pressure. As in conventional angioplastyprocedures, the third balloon 358 can be formed of a non-elasticrelatively non-compliant material so that high pressures as for example10-15 atmospheres can be used within the balloon to apply compressiveforces to the vessel without danger of rupturing the vessel. It shouldbe appreciated that the non-elastic capabilities can also be achieved bya composite elastic material.

[0141] Since the blood flow has been restored to the vessel 367 by theshunt hereinbefore described, the compression of the occlusion formingthe stenosis 369 can be carried out for an extended period of time, asfor example after a few minutes, if desired to help ensure that a largelumen or passageway is formed through the stenosis 369 as shown in FIG.16E. If it is believed that the occlusion forming the stenosis 369 hasbeen sufficiently compressed, the third balloon 358 can be deflated. Inthe event an inelastic balloon is utilized for the third balloon 358,and it is desired to utilize a larger third balloon, this can beaccomplished by removing the third tubular member 351 with the deflatedballoon 358 thereon and introducing a third tubular member 351 having alarger size balloon thereon over the second tubular member 331 andadvancing it into the stenosis 369 and inflating the larger size balloonto create a still larger passage through the stenosis 369.

[0142] After the appropriate dilation the stenosis 369 has beenaccomplished the third balloon can be removed from the stenosis whileaspiration of the working space 376 is still ongoing so that any plaquecoming off the occlusion forming the stenosis 369 can be aspirated outof the vessel. After the third balloon 358 has been removed from thestenosis, the second balloon 336 and the first balloon 319 can bedeflated to permit normal blood flow through the vessel 367 after whichthe arterial blood flow supply to the fitting 338 can be terminated. Theentire catheter assembly 311 can then be removed from the guidingcatheter 363 after which the guiding catheter 363 can be removed and asuture applied to the incision created to obtain access to the femoralartery.

[0143] In place of the third balloon 358 for causing compression of theocclusion forming the stenosis 367 to create a larger passagewaytherethrough, an atherectomy device 381 (see FIG. 17) can be utilizedfor operating in the working space 376 to remove the plaque of theocclusion forming the stenosis. This can be accomplished with a catheterassembly or apparatus 381 which in many respects is similar to theapparatus 311 shown in FIG. 11 and consists of a first tubular member316 with a first balloon 319 and a second tubular 331 with a secondballoon 336 thereon. In place of the third flexible elongate tubularmember 351 there is provided a third flexible elongate tubular member386 which is provided with proximal and distal extremities 387 and 388.The flexible elongate tubular member 386 is slidably and rotatablymounted in the central lumen 321 of the flexible elongate member 316 andis provided with a central or main lumen 389 through which the secondflexible elongate tubular member 331 extends. It is also provided with alumen 391 extending from the proximal extremity to the distal extremitythrough which a saline solution can be introduced for saline irrigationas hereinafter described. It is also provided with another lumen 392which is adapted to receive a plurality of electrical conductors 393 forperforming electrical functions as hereinafter described. The lumen 392is connected to a conventional Luer-type fitting 396 serving as a fluidirrigation fitting mounted on the proximal extremity first tubularmember 312 and is in communication with an annular recess 397 which isin communication with the lumen 391 provided in the tubular member 386for supplying a saline irrigation liquid through the flexible elongatetubular member 386 and into the working space 376 provided between thefirst and second balloons 316 and 336. In order to aid aspiration of thesaline irrigation liquid from the working space 376, the outer surfaceof the flexible elongate tubular member 386 is provided with a helicalgroove 398 therein which has one end which opens into the working space376 and which has the other end in communication with the aspirationfitting 327.

[0144] Means is provided for rotating the second tubular member 386 andconsists of suitable means such as a spur gear 401 mounted on theproximal extremity 387 of the tubular member 386. The spur gear 401 isdriven in a suitable manner as for example by another smaller spur gear402 which is of greater width than spur gear 401 so as to provide asplined gear connection between the gears 401 and 402. This accommodatesthe desired longitudinal movement for the tubular member 386 so that thedistal extremity 388 of the tubular member 386 can be advanced andretracted in the working space 376 as hereinbefore described. Anelectrical drive motor 403 is provided for driving the gear 402.

[0145] Atherectomy means 406 is provided on the distal extremity 388 ofthe flexible elongate tubular member 386. As shown in FIGS. 17 and 19,the atherectomy means 406 consists of a flexible elongate member 407formed of a suitable material such as stainless steel or preferably asuperelastic Nitinol. The flexible elongate member 407 is wound into ahelix as shown in FIG. 19 onto the distal extremity of the tubularmember 386. The flexible elongate member 407 can be formed of a ribbonhaving a thickness of 0.003″ and a width of 0.060″. One end of theflexible elongate member 407 can be secured to the tubular member 386,as for example by inserting the same into a slit 408 and additionally bythe use of adhesive (not shown). The flexible elongate member 407 iswrapped into a helix in a direction opposite to the direction of normalrotation of the tubular member 386 and can be provided with a specialtip 409 on its free end with the tip having an arcuate surface 411 thatis inclined rearwardly to terminate at a cutting edge 412 (see FIG. 19)which is adapted to engage the plaque or the stenosis 369.

[0146] When the distal extremity 388 of the flexible elongate tubularmember 386 has been introduced into the working space 376, the end ortip 409 of the flexible elongate member 407 of the atherectomy means 406is free. A saline solution is introduced into the fitting 357.Thereafter the motor 403 can be energized to cause rotation of thetubular member 386 and to thereby cause rotation of the helically woundflexible elongate member 407 to cause its free end or tip 409 to bemoved outwardly radially under centrifugal force to bring the cuttingedge 412 into engagement with the plaque 369 in the stenosis 369 tocause progressive removal of the plaque forming the stenosis 369 toenlarge the passageway extending through the stenosis. Because of therounded configuration of the tip 409, the tip 409 will not dig into thevessel wall but will only remove plaque which is engaged by the cuttingedge 412. As the plaque is being removed, the saline solution introducedthrough the fitting 396 into the space 376 picks up the plaque particlesor emboli as they are being removed. The saline solution with the plaqueor emboli therein is removed through the spiral groove 398 and throughthe aspiration port 327. The flexible elongate tubular member 386 can bemoved back and forth so that the cutting tip 409 engages the length ofthe stenosis 369 so that substantially all of the stenosis 369 can beremoved.

[0147] Means is provided to sense when sufficient plaque has beenremoved from the stenosis 369 and to ensure that cutting edge 412 doesnot cut into the vessel wall. An ultrasonic sensor 416 (see FIG. 17) ismounted in the distal extremity of the tubular member 386 and isconnected by conductors 393 (see FIG. 18) extending through the lumen392 and connected to a cable 418 which is connected to an ultrasonicpower supply 419 and a video monitor 421. By using the Doppler effect,ultrasonic energy can be utilized in connection with the transducer 416to ascertain the depth of cut being made by the flexible elongate member407 as it is being rotated.

[0148] As soon as a desired amount of plaque has been removed from thestenosis 369 to provide the desired passage through the stenosis,rotation of the tubular member 386 is terminated after which the tubularmember 386 can be withdrawn followed by deflation of the second balloon336 and withdrawing it. Deflation of the first balloon 316 then occursafter which it is withdrawn from the vessel 367. Thereafter, the guidingcatheter 363 can be removed and the incision closed as hereinbeforedescribed.

[0149] In order to ensure that restenosis will not take place, it may bedesirable to place a cylindrical stent 426 in the stenosis 369. Such astent 426 can be a self-expanding stent formed of a suitable materialsuch as a superelastic Nitinol and movable between unexpanded andexpanded conditions. Such a stent 426 can be placed by a suitablecatheter apparatus 431 of the type shown in FIG. 20. The stent 426 whichis cylindrical in form is pushed over the proximal extremity of thesecond elongate flexible tubular member 331 into the main or centrallumen 321 so that it is retained in the unexpanded position. It is thenpushed forwardly toward the distal extremity of the first flexibleelongate tubular member 316 by means of a flexible elongate tubularmember 436 having proximal and distal extremities 437 and 438 and havinga flow passage 439 extending from the proximal extremity 437 to thedistal extremity 438. The proximal extremity 437 is provided with aknurled collar 441 which is adapted to be engaged by the hand tofacilitate pushing of the flexible elongate tubular member 436 so thatits distal extremity is in engagement with the stent 426. Thus, whendesired the stent 426 may be discharged or dislodged from the distalextremity of the second tubular member 331 and pushed into the workingspace 376 created between the first balloon 319 and the second balloon336.

[0150] After the stent 426 has been discharged out of the end of thefirst flexible elongate tubular member 316, the stent 426 will selfexpand toward its expanded condition until it is in engagement with thewall of the vessel in the vicinity of the occlusion forming the stenosis369 to frictionally retain the stent in engagement with the vessel wall.As soon as the stent 426 is in engagement with the vessel wall, thesecond balloon 336 can be deflated as can the first balloon 319. Thefirst deflated balloon 336 can then be withdrawn through the interior ofthe cylindrical stent 426. This can be followed by deflation of thefirst balloon 319 and the removal of the flexible elongate tubularmember 316 with its first balloon 319 and the flexible tubular member331 with its second balloon 336, along with the flexible elongate member436 until the entire catheter assembly or apparatus 431 has been removedfrom the guiding catheter 363. Thereafter the guiding catheter 363 canbe removed and the incision sutured as hereinbefore described.

[0151] In FIG. 21, there is shown another embodiment of an apparatus 451incorporating the present invention which is particularly adapted foruse treating a stenosis at or near a bifurcation appearing in anarterial vessel. The apparatus 451 is shown being used on a human being452 showing the principal arteries and pulmonary veins of the humanbody. Thus there as shown, the abdominal aorta 453 branches into thecommon iliac 454 which branches into the external iliac 456 and theinternal iliac 457. The external iliac branches into the deep femoralartery 458 and into the femoral artery 459. The abdominal aorta 453extending in the opposite direction passes through the aortic arch 461of the heart 462. The aortic arch 461 is connected to the common carotid466 which extends into a bifurcation 467 branching into the externalcarotid 468 and the internal carotid 469. Similar bifurcations appear inthe basilar artery which is an artery which is particularly inaccessiblefor surgical treatment.

[0152] As hereinafter explained, the apparatus 451 shown in FIGS. 21, 22and 23 consists of a proximal occlusion balloon catheter 476 which canbe considered to be a first catheter. The catheter 476 is formed of aflexible elongate tubular member 477 having proximal and distalextremities 478 and 479. The tubular member 477 is formed of a suitablematerial such as plastic and can have a suitable size ranging from 5 to14 French and preferably 9 to 10 French. A balloon 481 is provided onthe distal extremity 479 and is formed of a suitable elastic material.It is generally cylindrical in form and has its proximal and distalextremities secured to the tubular member 477 by suitable means such asan adhesive (not shown). The tubular member 477 is provided with aplurality of lumens therein. One lumen 482 serves as a balloon inflationlumen and extends from the proximal extremity 478. It can have asuitable size such as 0.024″ and has port 483 in communication with theinterior of the balloon 481. A manifold 486 formed of a suitablematerial such as plastic is mounted on the proximal extremity 478. Atubular member 487 is mounted in the manifold 486 and is incommunication with the inflation lumen 482.

[0153] The tubular member 477 is also provided with a large lumen 491having a suitable size as for example 0.045″ which is adapted toslidably receive therein a therapeutic balloon catheter 492 and aperfusion balloon catheter 493. It is also provided with another lumen496 having a suitable size as for example 0.026″ which is adapted toreceive a balloon-on-a-wire catheter 497. It is also provided with anaspiration lumen 501 having a suitable size as for example 0.025″ and anirrigation lumen 502 having a suitable size as for example 0.015″. Thereis also provided another lumen 503 which can be used for other purposes.

[0154] The therapeutic balloon catheter 492 and the perfusion ballooncatheter 493 are constructed in a manner similar to the ballooncatheters hereinbefore described. Thus the perfusion balloon catheter493 is provided with a flexible elongate tubular member 506 havingproximal and distal extremities 507 and 508. A balloon 509 formed of anelastic material is secured to the distal extremity 508 by suitablemeans such as an adhesive (not shown) and is adapted to be inflatedthrough a port 510 in communication with a balloon inflation lumen 511.The tubular member 506 is also provided with a blood perfusion lumen 512which is centrally disposed therein. The proximal extremity 507 of thetubular member 506 is connected to a Y adapter or fitting 513 of whichthe central arm 514 is in communication with the blood perfusion lumen512 and is provided with a Luer-type fitting 516. The side arm 517 ofthe fitting 513 is in communication with the balloon inflation lumen 511and is provided with a Luer-type fitting 518 adapted to be connected toa source of pressure as hereinafter described.

[0155] The therapeutic balloon catheter 492 consists of a tubular member521 having a proximal and distal extremities 522 and 523. A balloon 524formed of a non-elastic material is secured to the distal extremity 523by suitable means such as an adhesive. A port (not shown) is incommunication with the interior of the balloon 524 and is incommunication with a balloon inflation lumen 526. A Luer-type fitting527 is mounted on the proximal extremity 522 and is in communicationwith the balloon inflation lumen 526. Another fitting 528 is mounted onthe proximal extremity 522 and is in communication with a largecentrally disposed lumen 529 which can receive the perfusion ballooncatheter 493 for slidable movement as hereinafter described.

[0156] The balloon-on-a-wire catheter 497 is slidably mounted in thelumen 496 and consists of a guide wire 531 of a conventionalconstruction having a suitable diameter as for example 0.018″ and havinga proximal and distal extremities 532 and 533. A balloon 534 formed of anon-elastic material is mounted on the distal extremity 533 and issecured thereto by suitable means such as an adhesive (not shown). Theproximal extremity of the balloon 534 is secured to the distal extremityof a tubular member 536 formed of a suitable material such as plasticand which is coaxially disposed on the guide wire 531. The tubularmember 536 extends the length of the guide wire to the proximalextremity and is connected to a Luer-type wye fitting 537 and is incommunication with an annular lumen 538 disposed between the tubularmember 536 and the exterior surface of the guide wire 531. The lumen 538is in communication with the interior of the balloon 534 for inflatingand deflating the balloon 534. The balloon-on-a-wire catheter 497 isadapted to be introduced through a fitting 541 carried by a tube 542mounted in the manifold 486 and in communication with the lumen 496 inthe multi-lumen elongate tubular member 477.

[0157] A tube 546 is mounted in the manifold 486 and is in communicationwith the large lumen 491 and is provided with a fitting 547 which isadapted to receive the perfusion balloon catheter 493 and thetherapeutic balloon catheter 492 as hereinafter described. Another tube551 is provided in the manifold 486 and is in communication with theaspiration lumen 501. It is provided with the fitting 552. Another tubefitting 553 is mounted in the manifold 486 and is in communication withthe irrigation lumen 502 and is provided with a fitting 554.

[0158] The various fittings for the catheter as hereinbefore describedare adapted to be connected into a control console 571. The controlconsole 571 consists of a rectangular case 572 which is provided with afront panel 573.

[0159] A plurality of balloon inflation deflation devices 576 of aconventional type typically called endoflaters are mounted within thecase 572 and have control handles 577 extending through verticallydisposed slots 578 provided in the front panel. These endoflaters 576are labeled as shown in FIG. 21 and are connected by tubing (not shown)through pressure gauges 581 mounted in the front panel 573 and areprovided with needle indicators 582 to indicate the pressure beingapplied by the endoflater to the tubing. The tubing is connected in sucha manner so that the endoflater 576 and the associated pressure gauge581 are connected to a tube 586 which is provided with a mating fitting587 adapted to mate with a fitting 488 so that it is in communicationwith the inflation lumen 482 of the proximal occlusion balloon catheter476. In a similar manner, the tubing 588 is provided with a fitting 589which mates with a fitting 518 of the balloon inflation lumen 511 of theperfusion balloon catheter 493 for inflating balloon 509. Similarly,tube 591 with its mating fitting 592 is adapted to mate with the fitting537 for inflating the balloon 534. Similarly, the tube 593 with itsfitting 594 mates with the fitting 527 in communication with the ballooninflation lumen 526 for inflating the balloon 524 of the therapeuticcatheter 492. Another tube 596 which is provided with its fitting 597mates with the fitting 552 that is in communication with the aspirationlumen 501. The tube 596 is in communication with the inlet of a bloodpump 601 of a suitable type as for example a roller pump well known tothose skilled in the art which is mounted within the case 572 and whichis connected to a source of electrical power through electrical plug 602connected into the case 572. The roller pump 601 is provided with anon/off switch 603 mounted on the front panel 573. After it passesthrough the pump 601, blood is supplied to a blood filter 606 of aconventional type and then is supplied through a tube 611 having afitting 612 adapted to mate with the fitting 516 of the perfusionballoon catheter which is in communication with the perfusion lumen 512.

[0160] A three-way valve 616 is associated with each of the endoflaters576 and has a control knob 617 extending through the front panel 573 andis adaptable to be moved between three positions with a center offposition and an aspiration position in a counter-clockwise direction anda pressurized position in a clockwise position as viewed in FIG. 24.

[0161] Operation and use of the apparatus 451 may now be brieflydescribed as follows. Let it be assumed that it is desired to treat astenosis occurring in a bifurcation in a carotid artery as depicted bythe illustrations shown in FIGS. 25A through 25D. As shown in theillustration in FIG. 25A, let it be assumed that a stenosis is presentadjacent the bifurcation 467 and in the external carotid 468 and that itis desired to treat this stenosis in accordance with the apparatus 451of the present invention in performing the method of the presentinvention. The proximal occlusion balloon catheter 476 is loaded withthe therapeutic balloon catheter 492 slidably mounted over the perfusionballoon catheter 493 and both are slidably mounted in the main lumen491. The balloon-on-a-wire catheter 497 is slidably mounted in thelumen. While the patient is being prepared for the procedure, all of thelumens in the catheters of the apparatus are flushed with saline toremove all air from the lumens. They are then connected to the controlconsole 571 in the manner hereinbefore described and as shown in FIG.21. An incision 626 (see FIG. 21A) is made in the femoral artery in theleft leg of the patient and a guiding catheter (not shown) similar tothe type utilized in angioplasty is introduced through the femoralartery 459. This guiding catheter is advanced until it is near the aortaarch 461. Thereafter, the first or proximal occlusion balloon catheter476 has its distal extremity 479 introduced into the guiding catheterand advanced in the guiding catheter. It is advanced so that its distalextremity 479 enters the common carotid and is near the bifurcation 467.The balloon 481 is inflated by operating the control handle 577associated with the proximal occlusion balloon 481 as shown in FIG. 25Ato create the desired pressure within and to inflate the elastic balloon481 so that it occludes the common carotid just proximal of the stenosis624. As soon as this occurs, the roller pump 601 is turned on byoperating the on/off switch 603 to create a negative pressure on thedistal side of the balloon 481 to cause blood to flow in a reversedirection as shown by arrows 627 to thereby change the directional flowof blood from the internal and external carotids away from the brainrather than to the brain. The blood travels into the aspiration lumen501 as indicated by the arrows 627 and into the tube 551 throughfittings 552 and 597 and tube 596 to the roller pump 603. The bloodafter passing through the roller pump 603 passes through a blood filter606 and then passes into the tube 611 and the fitting 612 and connectedto the fitting 589 of the perfusion catheter 493. Alternatively, thefitting 612 can be which is connected to another fitting 631 mounted ona tube 632 introduced into the venous side of the circulatory system ofthe patient's body, as for example into the vein in the right leg of thepatient 452 as shown in FIG. 21. Any debris or emboli in the aspiratedblood being pumped will be filtered out by the blood filter 606.

[0162] As soon as or during the time this retrograde circulation ofblood is established through the roller pump 601, the perfusion ballooncatheter 493 extending proximally from the fitting 547 is advanced intothe internal carotid 469 past the stenosis 621 at the bifurcation 467.If necessary, a guide wire can be utilized which can be introducedthrough the perfusion lumen 512 to aide in advancing the perfusionballoon catheter 493 into the internal carotid 469. Any emboli or debrisdislodged from the stenosis 621 by crossing the same either by the guidewire or by the distal extremity of the catheter 493 will be picked up bythe retrograde flow of blood which is being aspirated through theproximal occlusion balloon catheter 476 to thereby prevent any emboli ordebris from entering the brain of the patient. The elastic perfusionballoon 509 is then inflated as shown in FIG. 25B using the appropriateendoflater to inflate the balloon to the desired pressure while watchingthe associated pressure gauge. As soon as occlusion occurs, perfusion ofblood can be started as hereinafter described.

[0163] Prior to or after the balloon 509 of perfusion catheter 493 hasbeen inflated, the balloon-on-a-wire catheter 497 extending proximallyof the fitting 541 is advanced into the external carotid 469 as shown inFIG. 25C. The balloon 534 is then expanded by use of the appropriateendoflater to supply an inflating medium through the fitting 537 toocclude the external carotid 469. As soon as occlusion has beenaccomplished in both the external and internal carotids, retrograde flowof blood is terminated by shutting off the roller pump 601. It should beappreciated that if desired, automatic controls can be provided wherebywhen a certain pressure is reached in each of the balloons 509 and 534the roller pump would automatically be shut off to stop retrograde flow.By this procedure, it can be seen that the lesion of stenosis 621 hasbeen bracketed by the balloons 481, 509 and 534. Prior to thatoccurring, retrograde flow of blood is established to prevent any embolior debris from moving towards the brain.

[0164] As soon as retrograde flow of blood has been terminated,perfusion of blood is started. This can be accomplished by connecting acannula (not shown) to the fitting 516 of the perfusion catheter 506 andto obtain a supply of blood from the femoral artery in the other leg ofthe patient. Alternatively, an outside blood supply can be used. Thusfresh blood will be supplied from the femoral artery of the patientdirectly into the perfusion balloon so that it is discharged distally ofthe perfusion balloon 509 as shown by the arrows 628 to continue tosupply blood to the carotid artery. It has been found that it isunnecessary to a supply perfusion of blood to the external carotidartery because there is sufficient auxiliary circulation in that carotidartery during the time the procedure is taking place.

[0165] In the event there is inadequate pressure on the arterial bloodbeing perfused to overcome the resistance in the lumen 469, the rollerpump 601 can be utilized by merely operating the same in a reversedirection and connecting it between the cannula and the perfusioncatheter.

[0166] After the lesion or stenosis 621 has been bracketed ashereinbefore described and a working space 636 formed adjacent thestenosis or lesion 621, a therapeutic procedure can be employed. By wayof example this can consist of advancing the therapeutic ballooncatheter 492 over and axially of the perfusion catheter 493 to bring itsballoon 524 into registration with the stenosis 621 as shown in FIG.25D. Thereafter, the balloon 524 can be inflated by use of theappropriate endoflater as hereinbefore described to cause the inelasticballoon to be pressurized to a pressure of 10 to 15 atmospheres tocompress the stenosis 621. Prior to or during this procedure it may bedesirable to introduce a saline or heparin solution or a radiopaquecontrast liquid into the working space 636. This can be accomplished byintroducing this liquid through the injection lumen 502. If desired,this can be accomplished prior to terminating the aspiration procedurehereinbefore described. Also it should be appreciated that if desired asmall endoscope can be inserted through one of the lumens to view thearea within the working space. Alternatively, if desired an ultrasonicprobe can be utilized to view the area in which the lesion is disposed.

[0167] As hereinbefore described with a previous embodiment, in place ofthe therapeutic balloon catheter, other types of catheters can beutilized as for example one incorporating an atherectomy device of thetype hereinbefore described to facilitate removal of the stenosis. It isreadily apparent that during these procedures if it is necessary tosupply a saline solution or a heparinized solution into the workingspace that the working space can also be continued to be aspirated toremove any debris or emboli which occur during the procedure.

[0168] Let it be assumed that the desired therapeutic actions have beenundertaken and that the stenosis 621 has been reduced and substantiallyeliminated so that there is adequate flow through the internal carotid.If it can be seen that there also is a stenosis in the external carotid,the balloon-on-a-wire catheter 497 and the perfusion catheter 493 can bewithdrawn and moved so that they enter the opposite carotid to permittherapeutic treatment of a stenosis occurring in the other carotid.

[0169] When all the desired therapeutic procedures have beenaccomplished, the supply of saline or contrast solution can beterminated and the therapeutic balloon 524 deflated. The balloon 534 ofthe balloon-on-a-wire catheter can be deflated as well as the perfusionballoon 509. Perfusion of blood through the perfusion catheter can beterminated. The perfusion balloon catheter 493 and the balloon-on-a-wirecatheter 497 can be retracted into the main multi-lumen tubular member477 of the proximal occlusion balloon catheter after which the perfusionballoon catheter can be withdrawn carrying with it the other cathetersdisposed therein. Thereafter, the guiding catheter can be removed and asuture applied to the incision made to gain access to the femoralartery.

[0170] It is readily apparent that similar procedures can be carried outwith respect to other vessels in the body, such as saphenous vein graftsin the heart, and particularly with respect to vessels in the brainwhere it is difficult if not impossible to employ surgical procedures asfor example with respect to the basilar arteries in which bifurcationsappear.

[0171] As also herein before explained, the catheter apparatus of thepresent invention can be utilized for deploying stents. Where that isdesirable the apparatus of the present invention, perfusion can beaccomplished during employment of the stent.

[0172] From the foregoing it can be seen that an apparatus and methodhas been provided for treating occluded vessels and particularly fortreating carotid arteries. The apparatus and method of the presentinvention is particularly advantageous for the carotid arteries becauseit permits access to portions of the carotid arteries which are notaccessible by surgery.

[0173] The catheter apparatus assembly and method of the presentinvention are also particularly useful for treating other occludedvessels but particularly the carotid arteries because it makes possiblethe removal of plaque without endangering the patient. An operating orworking space is provided while shunting blood around the working spaceso that there is continued blood flow in the vessel to support thefunctions which are normally supported by the vessel. As also pointedout above, the apparatus and method of the present invention areparticularly useful in connection with vessels having bifurcationstherein and in which the stenosis occurs at or near the bifurcation.From the foregoing it can be seen with the apparatus and method of thepresent invention, retrograde flow of blood is accomplished duringdeployment of the device to prevent undesired travel of emboli.Occlusion of the vessels is provided to obtain a working space bybracketing the working space with balloons while at the same timemaintaining perfusion of blood making it possible to utilize asubstantial period of time for undertaking therapeutic procedures withrespect to the bracketed stenosis.

[0174] In connection with the present apparatus and method for treatingoccluded vessels, it has been found that it is possible to utilize theapparatus and method without perfusion and other procedures involvingthe carotid arteries and saphenous vein grafts for periods of timeextending over five minutes and greater which has made it possible tosimplify the apparatus and the method utilized in conjunction therewith.

[0175] With respect to an apparatus or assembly which does not requirethe use of perfusion, a main catheter 651 utilized as a part of theapparatus is shown in FIGS. 26, 27, 28 and 29 consists of a flexibleelongate tubular member 652 formed of a suitable material such asplastic of the type hereinbefore described and which has proximal anddistal extremities 653 and 654. The tubular flexible elongate tubularmember 652 can be of various sizes as for example for a saphenous veingraft catheter it can be 8 to 9.5 French in balloon profile with alength ranging from 80 cm to 120 cm. The flexible elongate tubularmember 652 can be formed of a suitable material such as PEBAX, Nylon,Hytrel, polyurethane or polyethylene. A flexible braid 656 (see FIGS.27, 28 and 29) formed of a suitable material such as stainless steel isembedded within the wall of the flexible elongate tubular member 652 asshown and extends from the proximal extremity 653 to the distalextremity 654. The braid 656 can be formed of a suitable stainless steelsuch as a wire or ribbon having a thickness of 0.001″. The braid 656provides additional torquability and also inhibits the kinking of theflexible elongate tubular member 652 when it must extend over a tightradius. The flexible elongate tubular member 652 is provided with alarge central lumen 657 having a suitable diameter such as 0.065 orgreater″ extending from the proximal extremity to the distal extremity.

[0176] If it is desired to provide a flexible elongate member 652 whichhas a greater flexibility at the distal extremity, a different materialcan be used in the distal extremity 654. For example, the distalmost5-15 centimeters can be formed of a material such as PEBAX having aShore D hardness of 35-50 with the remainder of the flexible elongatemember 652 having a Shore D hardness of 65-75.

[0177] A supplemental flexible elongate tubular member 661 is providedwhich has incorporated therein a balloon inflation lumen 662. Thesupplemental flexible elongate tubular member 661 can be of a suitablesize as for example an I.D. of 0.014″ and an O.D. of 0.018″ and formedof a suitable material such as a polyimide. The supplemental flexibleelongate tubular member has a length which is almost as long as theflexible elongate tubular member 652 and overlies the outside wall ofthe flexible elongate tubular member 652 and extends from the proximalextremity to near the distal extremity as shown in FIGS. 26 and 29. Atube 663 of a suitable material such as Pebax extends over the length ofthe polyimide tubing 661 and is secured to the flexible elongate tubularmember 652 by a shrink tube 666 extending from the proximal extremity653 to the distal extremity 654, after which the shrink tube 663 issubjected to heat. The shrink tube 666 is then subjected to a hot meltprocess of a temperature around 350° F. for a period of time until thePebax tube 663 melts, after which the shrink tubing 666 can be strippedoff so that there remains a relatively uniform mass formed of Pebax thatsurrounds the braid 657 and the polyimide tube 661 which forms thesupplemental flexible elongate tubular member 661. The polyimide tubewhich forms the supplemental flexible elongate tubular member 661 thusprovides an inflation lumen 667 extending from the proximal extremityand to the distal extremity and opens through an opening 668 into theinterior of an occlusion balloon 669 which is bonded to and coaxiallymounted on the distal extremity of the flexible elongate member 652 inthe manner shown in FIG. 29. The polyimide tubing is provided to givethe balloon inflation lumen shaft 361 greater strength than that whichis provided by the Pebax itself.

[0178] As can be seen from FIG. 29, the supplemental flexible elongatetubular member 661 is terminated short of the distalmost extremity ofthe flexible elongate tubular member 652 by approximately 1 cm. Theocclusion balloon 669 is formed of various compliant or non-compliantmaterials. Suitable compliant materials include elastomers such asC-Flex latex, silicones and polyurethanes. Suitable non-compliantmaterials would be polyethylene, PET and Nylon. A composite material canalso be used such as a combination of PET and an elastomer. Theocclusion balloon 669 should have a strength so that it can readilyaccommodate any pressure of one atmosphere and as high as fouratmospheres, or approximately 60 psi. The occlusion balloon 669 iscylindrical and is provided with proximal and distal extremities 671 and672 which are secured by a suitable medical grade adhesive.Alternatively, fuse bonding may be used. Thus a seal 673 formed of thisadhesive bonds the proximal extremity 671 of the occlusion balloon 669over the outer surface of the distal extremity of the flexible elongatetubular member 652 and the supplemental flexible elongate tubular member661. Similarly, a seal 674 bonds the distal extremity 672 to the distalextremity of the flexible elongate tubular member 652 to provide anair-tight space within the balloon accessible through the opening 668. Asoft cylindrical tip 676 formed of suitable material such as Pebax isbonded to the distal extremity of the flexible elongate tubular member652 and is provided with a rounded surface 677 which extends forwardlyand has a passage 678 therein in communication with the lumen 657 andthe flexible elongate tubular member 652. A cylindrical radiopaquemarker 681 formed of a suitable material such as platinum,platinum-iridium or gold is mounted on the distal extremity of theflexible elongate tubular member 652 in a position so it issubstantially equidistant of the ends of the occlusion balloon 669.

[0179] A main adapter or fitting 686 formed of a suitable material suchas plastic is mounted on the proximal extremity 653 of the flexibleelongate tubular member 652. It is provided with a first Luer fitting687 which provides a balloon inflation port 688 in communication withthe balloon inflation lumen 662. It is also provided with another Luerfitting 689 which is provided with an aspiration port 691 incommunication with the main central lumen 657. The main adapter 686 isalso provided with a Tuohy-Borst fitting 692 which is in communicationwith the central lumen 657. The Tuohy-Borst fitting 692 is adapted toreceive therapeutic devices, as for example a balloon-on-a-wire deviceas hereinafter described and is adapted to form a liquid-tight sealtherewith by an o-ring 693.

[0180] A balloon-on-a-wire device 701 incorporating the presentinvention is shown in FIGS. 30 and 31. The device 701 consists of aguide wire 702 formed of a suitable material such as stainless steel andhaving a suitable diameter as for example ranging from 0.010″ to 0.032″but preferably a diameter ranging from 0.014″ to 0.018″. It ispreferable that the guide wire 702 be formed of a nickel titanium alloytypically called Nitinol which has the advantage that it is moreflexible and has greater kink resistance characteristics than anothersuitable material such as stainless steel.

[0181] It has a suitable length as for example 150 cm. The guide wire702 is provided with proximal and distal extremities 703 and 704 and isprovided with a central lumen 706 extending from the proximal extremityto the distal extremity. The lumen can be of a suitable size as forexample 0.010″ I.D. for an 0.014″ O.D. guide wire.

[0182] An occlusion balloon 711 is coaxially mounted on the distalextremity 704 of the guide wire 702. The occlusion balloon 711 ispreferably formed of the same material as the occlusion balloon 669 onthe main catheter 651. The occlusion balloon 711 has proximal and distalextremities 712 and 713. A tube 716 formed of a suitable material suchas a polyimide is disposed within the occlusion balloon 711 and has abore 717 extending therethrough which is sized so that it is slightlylarger than the outside diameter of the guide wire 702 so that itsproximal extremity can be slipped over the distal extremity 704 of theguide wire 702 and then bonded thereto by suitable means such as anadhesive 718. A plurality of circumferentially spaced apart radiallyextending inflation holes 719 are provided in the proximal extremity ofthe tube 716 and are in alignment with similarly spaced holes 721provided in the distal extremity 704 of the guide wire 702 so that theyare in communication with the central lumen 706 of the guide wire 702.The inflation holes 719 as shown are in communication with the interiorof the occlusion balloon 711 so that fluid passing from the passage 706can be utilized for inflating the occlusion balloon 711.

[0183] A solid core wire 723 formed of a suitable material such asstainless steel is provided with a proximal tapered extremity 724. Thecore wire 723 is sized so it is adapted to fit within the lumen 706 ofthe guide wire 702 and is secured therein by suitable means such as anadhesive 726 or alternatively a weld. The core wire 723 has a taperedportion 723 a which commences at the proximal extremity 724 and which istapered so that the cross-sectional diameter progressively decreases tothe distal extremity of the occlusion balloon 711. The core wire 723 isalso provided with additional portions 723 b and 723 c which can be ofsubstantially constant diameter as for example 0.003″. The portion 723is folded over with respect to the portion 723 b so that the portions723 b and 723 c lie in a plane to facilitate shaping of the distalextremity of the guide wire 702 during use of the same. The core wire723 is provided with a distal extremity 727 in which a bend 728 isformed between the two portions 723 b and 723 c. The bend 728 is securedwithin a hemispherical solder bump or protrusion 729 which is carried bythe distal extremity of a coil 731 formed of a suitable radiopaquematerial such as platinum or a platinum alloy. The platinum coil 731 canhave a suitable outside diameter as for example 0.014″ corresponding tothe diameter of the guide wire 702 and can have a suitable lengthranging from 1 to 3 cm. The proximal extremity of the coil 731 issecured to the distal extremity of the polyimide tube 716 by suitablemeans such as an adhesive 732 which can be the same adhesive or adifferent adhesive 733 utilized for securing the distal extremity 713 ofthe balloon to the polyimide tube 716 to form a fluid-tight seal betweenthe distal extremity of the occlusion balloon 711 and the distalextremity of the polyimide 716. From this construction it can be seenthat the portions 723 b and 723 c of the core wire 723 in addition toserving as a shaping ribbon are also utilized as a safety ribbon toensure that the tip 728 and the spring 731 cannot be separated from theguide wire 702. The proximal extremity 712 of the balloon 711 is alsosecured to the proximal extremity of the polyimide tube 716 and also tothe distal extremity 704 of the guide wire 702 to form a fluid-tightseal with respect to the occlusion balloon 711 so that the occlusionballoon 711 can be inflated and deflated through the inflation holes 719and 721.

[0184] Alternative constructions for the distal extremity of the corewire 723 are shown in FIGS. 33 and 34. In FIG. 23 it can be seen thatthe portions 723 b and 723 c have been twisted to in effect provide atwisted pair serving as a safety ribbon and as a shaping ribbon. In theembodiment shown in FIG. 34, the core wire 736 is provided with atapered portion 736 a which is the same as the tapered portions of 723 ahereinbefore described. However, the core wire 736 has been providedwith a distal portion 736 b which has been flattened to a suitablethickness as for example a width of 0.006″ and a thickness of 0.003″ andthen twisted to form a helix as shown in which the distal extremity isembedded within the solder 729. Such a helix 736 can serve as a safetyribbon and also can be shaped to some extent.

[0185] A removable inflation fitting 741 or valve attachment 741 ismounted on the proximal extremity of the guide wire 702 and forms a partof the balloon-on-a-wire device 701. The fitting or attachment 741 isformed of a suitable material such as a polycarbonate and is providedwith a central bore 742. The attachment or fitting is slid externallyover the proximal extremity 703 of the guide wire 702. Means is providedfor forming a fluid-tight seal between the proximal extremity 703 of theguide wire 702 and a body 743 of the fitting 741 and consists of ano-ring 746 (see FIG. 35) seated in a well 747. A thumb screw 748 isthreadedly mounted on the body 743 and is provided with an inwardlyextending circular protrusion 749 that is adapted to engage the o-ring746 and to compress the same to form a fluid-tight seal when theprotrusion 749 is moved inwardly toward the o-ring 746 as the thumbscrew 748 is rotated in a clockwise direction. The o-ring 746decompresses or springs back when released upon rotation of the thumbscrew 748 in a counterclockwise direction so that the fitting 741 can beremoved from the distal extremity 703 of the guide wire 702. The body742 also includes a Luer fitting 751 which provides an inflation port752 that is in communication with the bore 742 in the body 743 and whichis also in communication with the open proximal extremity of the guidewire 702 and the lumen 706 therein.

[0186] Means is provided for plugging the bore 706 when the removableattachment or fitting 741 is removed and consists of a plug mandrel 756formed of a suitable material such as 0.014″ stainless steel solid rod.It is necessary that this rod have a diameter which is greater than thediameter of the lumen 706 and the guide wire 702. The plug mandrel 756is provided with a progressive portion 756 a that tapers down from as,for example from 0.014″ to a suitable diameter as for example 0.008″ toa cylindrical portion 756 b.

[0187] Means is provided for forming a fluid-tight seal between the plugmandrel 756 which forms a plug mandrel and the body 743 of theattachment or fitting 741 and consists of an o-ring 766 providingsuitable sealing means seated within a well 762 provided in the body743. A thumb screw 763 threadedly engages the body 743 and is providedwith a cylindrical protrusion 764 which engages the o-ring andcompresses it to form a fluid-tight seal with respect to the plugmandrel 756 by rotation in a clockwise direction of the thumb screw 763.The plug mandrel 756 can be released by a counterclockwise rotation ofthe thumb screw 763 permitting decompression of the o-ring 761.

[0188] An irrigation catheter 766 incorporating the present invention isshown in FIG. 36 and consists of a flexible elongate tube 767 formed ofa suitable material such as polyethylene, PEBAX, Hytrel or Teflon havinga suitable size as for example an outside diameter of 0.066″ and aninside diameter of 0.058″ and having a length of approximately 150 cm. Alumen 768 is provided therein and extends from the proximal extremity tothe distal extremity and is in communication with an adapter 769provided on the proximal extremity of the tube 767. The adapter 769 isprovided with a body 770 formed of a suitable material such as plasticand is provided with a bore 771 extending therethrough. The adapter 769is provided with a side arm 772 which carries a conventional Luer-typeconnection and provides an irrigation port 773 in communication with thebore 771. A thumb screw 774 threadedly mounted on the body 770 carries acylindrical protrusion 776 adapted to compress an o-ring 777 carried bythe body 770 into engagement with a therapeutic catheter of the typehereinafter described. A radiopaque tip marker 778 of a suitable type,as for example one formed as a platinum-iridium band 778 is provided onthe distal extremity of the flexible elongate element 767 to facilitatepositioning of the irrigation catheter as hereinafter described.

[0189] Operation of the apparatus shown in FIGS. 26 through 36 inperforming the method of the present invention for treating occludedvessels may now be briefly described as follows utilizing the cartoonswhich are shown in FIGS. 37-43. Let it be assumed that it is desired totreat a vessel 781 in the human body as for example a saphenous veingraft having at least a partial occlusion or stenosis 782 which isformed by plaque in the vessel. The main catheter 651 is introduced intothe body through a conventional procedure such as for example by makingan incision into the femoral artery in a leg of the patient.

[0190] Thereafter the main catheter 651 can be introduced into thefemoral artery by use of a large conventional guiding catheter becausethe main catheter 651 is of a relatively large size, as for example 8 to9.5 French. In order to eliminate the need for such a large guidingcatheter, a smaller conventional guiding catheter 786 of the type shownin FIG. 37 can be utilized which can be introduced through the maincatheter 651. Utilizing such a catheter, the main catheter 651 can beinserted independently through a conventional sheath (not shown) in thefemoral artery and thereafter the guiding catheter 786 is introducedthrough the main catheter 651 so that its distal extremity 789 is in thevessel. Alternatively, the guiding catheter 786 can be deployed into themain catheter 651 and the guiding catheter 786 introduced at the sametime into the femoral artery.

[0191] The guiding catheter 786 is conventional and thus will not bedescribed in detail. It consists of a flexible elongate tubular member787 (see FIG. 37) formed of a suitable material such as plastic havingproximal and distal extremities 788 and 789. The distal extremity 789 isprovided with a preformed bend as shown. An adapter 792 is mounted onthe proximal extremity 788 and consists of a body 793 in the form a wyein which the central leg 794 is provided with a flow passage (not shown)therein in communication with the central lumen (not shown) extendingfrom the proximal extremity 788 to the distal extremity 789 of theflexible elongate tubular member 787. The body 793 is provided with aside leg 796 which also is in communication with a lumen (not shown)extending from the proximal extremity 788 to the distal extremity 789. Aknob 797 carrying an o-ring (not shown) secures the adapter 792 to theproximal extremity 788 with a fluid-tight seal. Another knob 798 isprovided which is carried by the central leg 794 of the body 793 and isprovided with an o-ring (not shown) which can be moved to close the flowpassage in the central leg 794, or alternatively it can be opened toreceive a guide wire which can be utilized for advancing the guidecatheter 786 if that be necessary and then forming a fluid-tight sealwith respect to the guide wire.

[0192] Assuming that the guiding catheter 786 has been inserted into themain catheter 651 before insertion of the main catheter 651 into thefemoral artery, both catheters can be inserted in unison while advancingthe distal extremity of the guide catheter 786 so that it precedes thedistal extremity of the main catheter 651 and serves to guide the maincatheter 651 into the vessel of interest, as for example the vessel 781having the stenosis 782 therein. The main catheter 651 is then advancedso that its distal extremity is at the proximal side of the stenosis782. By way of example, the main catheter 651 can be advanced throughthe aortic arch of the heart and thence into a saphenous vein graft sothat the occlusion balloon 669 on its distal extremity is positionedproximal of the stenosis 782. As soon as this has been accomplished, theguiding catheter 786 can be removed.

[0193] As soon as the distal extremity of the main catheter 651 has beendeployed so that it is just proximal of the stenosis 782 to be treated,an assembly shown in FIG. 38 is introduced into the main catheter 651.This assembly can be provided by preloading the irrigation catheter 766onto the therapeutic catheter 801 by inserting the distal tip of thetherapeutic catheter 801 through the fitting 769 of the irrigationcatheter 766 and advancing the therapeutic catheter 801 until itstherapeutic balloon 809 exits from the irrigation catheter 766. Theballoon-on-a-wire catheter 701 also is preloaded by removing the valveattachment 746 and then inserting the proximal end 703 into the guidewire lumen at the distal tip of the therapeutic catheter 801 and thenadvanced proximally until the proximal end protrudes out of the proximalend of the therapeutic catheter. The valve attachment 741 is thenreattached to the proximal end 703. The preassembled irrigation catheter766, the therapeutic catheter 801 and the balloon-on-a-wire catheter 701are then introduced in unison as an assembly into the main catheter 651.The balloon-on-a-wire device 701 is then advanced until the distalextremity is near the distal extremity of the main catheter 651 butbefore the distal extremity has been advanced through the stenosis 782.

[0194] Let it be assumed that it is now desired to inflate the occlusionballoon 669 carried by the main catheter 651. This can be accomplishedin a suitable manner such as with an inflation-deflation devicerepresented schematically by a syringe 802 secured to the fitting 687(see FIG. 38) and supplying a balloon inflation fluid through theballoon inflation lumen 662 to inflate the occlusion balloon 669 to anocclusion pressure ranging from 1 to 3.9 atmospheres and preferablyapproximately one to two atmospheres to engage the side wall forming thevessel 781 to occlude the vessel 781 and to prevent further blood flowthrough the vessel and to thereby provide a working space 803 distal ofthe occlusion balloon 669. As soon as the occlusion balloon 669 has beeninflated, the balloon-on-a-wire device 701 can be advanced across thelesion or stenosis 782 until the deflated occlusion balloon 711 carriedthereby is distal of the stenosis 782. It is safe to cross the stenosis782 because the flow of blood through the stenosis 782 has been occludedby the occlusion balloon 669. Thus if any of the plaque forming thestenosis is dislodged by the occlusion balloon 711 on theballoon-on-a-wire device 701 as the occlusion balloon 711 is crossingthe stenosis 782, the plaque particles or emboli 804 will not be carriedoff by blood. The positive pressure of blood in secondary collaterals orvasculature will prevent emboli from traveling downstream into thesecondary vasculature. If desired, aspiration can be supplied to theworking space 803 encompassing the stenosis 782 by placing a suitablevacuum connected to the fitting 689 of the main catheter.

[0195] The occlusion balloon 711 can then be readily inflated by use ofa syringe 805 secured to the fitting 751 of the removable valve fittingor attachment 741 of the balloon-on-a-wire device 701 proximal of thefitting 686 and accessible outside the body of the patient. Theocclusion balloon 711 is inflated (see FIG. 39) to at leastapproximately one to two atmospheres to bracket the stenosis and todetermine the size of the working space 803 to provide a chamber. Itshould be appreciated that the size of this working space or chamber 803can be adjusted by changing the position of the occlusion balloon 711 inthe vessel 781. If desired, this can be accomplished while the occlusionballoon 711 is inflated.

[0196] Now let it be assumed that the occlusion balloon 711 has beeninflated with the appropriate working space 803 and that it is desiredto introduce a therapeutic balloon catheter 801 into the working space803 to treat the stenosis 782. If the therapeutic catheter 801 is not inthe main catheter 651 as hereinbefore described, this can be readilyaccomplished in the present invention by inserting a plug mandrel 756into the open end of the lumen 706 of the guide wire 702. After the plugmandrel 756 has been inserted, the syringe 805 can be removed afterwhich the thumb screws 748 and 763 can be loosened to permit the o-ringstherein to become decompressed and to release the guide wire 702 and theplug mandrel 756 to permit the fitting or valve attachment 741 to beslipped off to provide a proximal end on the guide wire 702 which isfree of obstructions. During removal of the valve attachment or fitting741, the occlusion balloon 711 remains inflated and continues to bedisposed distally of the stenosis 782. The occlusion balloon 669 alsoremains inflated because the syringe 802 remains attached to the fitting686 and is disposed proximal of the stenosis 782.

[0197] The conventional therapeutic catheter 801 then can be deliveredover the guide wire 702 if it is not already present. The therapeuticcatheter 801 is provided with a flexible elongate tubular member 806having proximal and distal extremities 807 and 808 with a central flowpassage (not shown) extending between the same. A therapeutic balloon809 on its distal extremity is adapted to be inflated to therapeuticpressures ranging from 4-20 atmospheres through a balloon inflationlumen (not shown) carried by the flexible elongate tubular member 806through an adapter 811 mounted on the proximal extremity 807. Thetherapeutic balloon 809 can be considered to be means for performingwork carried by the distal extremity 808 of the flexible elongatetubular member 806. The adapter 811 can be removable of the typehereinbefore described or alternatively can be permanently attachedthereto. Assuming that it is a removable adapter, the removable adapter811 is provided with knobs 812 and 813 carrying o-rings (not shown)adapted to establish fluid-tight seals with the flexible elongate member806 and the plug mandrel 756, respectively. It is also provided with aninflation port 816 similar to those hereinbefore described which is incommunication with the inflation lumen (not shown) provided in theflexible elongate tubular member 806 for inflating the therapeuticballoon 809.

[0198] After the balloon catheter 801 has been positioned by the use ofradiopaque markers (not shown) conventionally employed in such devices,the therapeutic balloon 809 is disposed so that it is in generalalignment with the stenosis 782 as shown in FIG. 39. The therapeuticballoon 809 is then inflated in a conventional manner to perform work byuse of an inflation-deflation device schematically represented by thesyringe 817 attached to the inflation port 816 to the desired pressureto compress the plaque forming the stenosis 782 as shown in FIG. 40 toincrease the size of the opening through the stenosis 782 in the vessel781.

[0199] Let it be assumed that during the compression of the plaqueforming the stenosis 782, additional emboli 804 are formed as shown inFIG. 41 by pieces of plaque becoming dislodged from the plaque 782within the vessel 781. Let it also be assumed that it is desired toremove these emboli before deflation of the occlusion balloons 669 and711 disposed proximally and distally of the stenosis 782. To accomplishthis, the therapeutic balloon 809 is deflated by use of the syringe 817.As soon as this has been accomplished, a saline solution can beintroduced through the irrigation catheter 766 by connecting a tube 819carrying the saline solution from a suitable source as for example afree or pressurized saline bag (not shown) and delivered through theirrigation port or side arm 772 where it is carried through the largecentral lumen of the irrigation catheter 766 so that the saline solutionis discharged into the working space 803 disposed between the occlusionballoons 711 and 669 as shown in FIG. 41. At the same time suitableaspiration means is connected to the aspiration port 689 of the adapter686 and as shown can consist of a hand operated bulb 821 which has a oneway check valve 822 therein connected to the fitting 689.

[0200] The bulb 821 is provided with another one-way check valve 823which is connected to a flexible collection bag 824. The bulb 821 makesit possible to generate a vacuum corresponding approximately to 3-30″ ofmercury. Thus, by compressing the bulb 821 by hand, it is possible tocreate suction within the chamber or space 803 formed in the vesselbetween the occlusion balloons 669 and 711 each time the bulb 821 iscompressed and released. Alternatively, the aspiration can beaccomplished by use of a syringe in place of the bulb 821 and thecollection bag 824. Saline liquid supplied through the irrigationcatheter 766 carrying the emboli 818 is aspirated through the centrallumen 657 of the main catheter 651. The aspirated liquid in each cycleof operation created by pressing the bulb 821 is delivered to thecollection bag 824. With such a procedure it has been found that it ispossible to aspirate emboli as large as 600 μm. Such removal can beassured by observing when clear liquid exits outside the body from theaspiration port 691. A chamber having a length ranging from 3 cm to 15cm can be totally cleared of emboli within a short period of timeranging from 5 to 30 seconds. Alternatively, irrigation can beaccomplished by removing the therapeutic catheter 801 after deflatingthe therapeutic balloon 809. The irrigation catheter can be advancedover the balloon-on-a-wire device 701 until the distal tip is justproximal of the occlusion balloon 711 as shown in FIG. 42 to provide agreater flow of saline and faster aspiration.

[0201] After all of the emboli 804 have been removed, introduction ofsaline through the tube 819 is halted. It should be appreciated that theports for irrigation and aspiration can be reversed in function ifdesired. Thereafter, the occlusion balloon 711 is deflated by removingthe plug 756 and utilizing a syringe 805, after which the occlusionballoon 669 is deflated permitting blood flow to be reestablished in thevessel 781. Alternatively, the occlusion balloon 669 can be firstdeflated and aspiration commenced at that time, permitting embolitrapped distally of the occlusion balloon 669 by blood flowing from theproximal side of the occlusion balloon 669 to be aspirated through thecentral lumen 657. In order to prevent excessive expansion of the vessel781 being treated, the pressure of the irrigation liquid is typicallymaintained under 30 psi. This pressure preferably should be below theocclusion balloon pressure.

[0202] If it is desired to deliver a stent to the site of the stenosisformed by the plaque 782, this can be readily accomplished during thesame procedure. Typically it is desirable to permit the blood to flownormally for a period of several minutes after which the occlusionballoon 669 can be reinflated by the syringe 805 and the occlusionballoon 711 can be reinflated by inserting the removable valveattachment 741 if it has been removed of the balloon-on-a-wire device701 and utilizing the syringe 803 to reinflate the occlusion balloon711. The plug mandrel 756 can be inserted to keep the occlusion balloon711 inflated after which the valve attachment 741 can be removed.

[0203] A conventional stent delivery catheter 826 carrying a stent 827on its flexible shaft 828 is introduced over the balloon-on-a-wiredevice 701 and delivered to the site of the dilated stenosis 782 (seeFIG. 43). The stent 827 can be of the self-expanding type or of the typewhich can be expanded by a balloon (not shown) carried by the catheter826 by connecting a syringe 829 to an adapter 830 of the typehereinbefore described of the stent delivery catheter 826. After thestent 827 has been deployed in the dilated stenosis 782, the stentdelivery catheter 826 can be removed after which the occlusion balloon711 can be deflated followed by deflation of the proximal balloon 661 inthe manner hereinbefore described. Also it should be appreciated that ifdesired in connection with the deployment of the stent delivery catheter826 before it is removed but after deflation of its balloon (not shown),it may be desirable to again flush the working space or chamber 803between the occlusion balloons 669 and 711 of emboli which may bedislodged during the delivery and deployment of the stent. Theirrigation catheter 766 can be deployed in the same manner ashereinbefore described with a saline irrigation solution supplied to theworking space 803 in the manner hereinbefore described and liquidaspirated therefrom by the use of the bulb 821 in the mannerhereinbefore described.

[0204] Heretofore the apparatus of the present invention has beenutilized for performing a procedure on a saphenous vein graft wherethere are no branches to be dealt with. An apparatus incorporating thepresent invention also can be useful in connection with vessels in ahuman being having branches therein, as for example the carotids. Forthis purpose, a main catheter 831 (see FIG. 44) is provided which isvery similar to the main catheter 651 with the exception that theadapter 832 provided on the proximal extremity is provided with catheterports 833 and 834 which are in communication with the large centrallumen 657 extending the length of the main catheter. The catheter ports833 and 834 have a construction similar to the exchange catheter andtherapeutic catheter port 692 hereinbefore described in connection withthe main catheter 651. These two catheter ports 833 and 834 arenecessary because in a carotid procedure, two balloon-on-a-wire devicesare utilized. The main catheter should be larger, as for example aslarge as 12 French, to provide a larger central lumen to accommodate thetwo balloon-on-a-wire devices.

[0205] One of the balloon-on-a-wire devices can be substantiallyidentical to the balloon-on-a-wire device 701 described. The otherballoon-on-a-wire device 835 as shown in FIG. 45 differs from the device701 shown in FIG. 30 in that in place of the removable valve attachment741 there is provided a fixed adapter 836 which consists of a body 837provided with diametrically extending wings 838 to facilitate graspingof the adapter 836. The body 837 is provided with a bore 839 which is incommunication with the lumen 706 in the guide wire 702. The adapter isprovided with a Luer-type fitting 840 to provide a balloon inflationport.

[0206] Operation and use of the apparatus of the present invention inperforming a procedure in a carotid artery is shown in the cartoons inFIGS. 46-50. Let it be assumed that it is desired to perform a procedurewith the apparatus of the present invention on a carotid artery in apatient, as for example common carotid 841 which branches into anexternal carotid 842 and an internal carotid 843 and that there is anarrowing or a stenosis 844 in the internal carotid 843 near thebifurcation into the external and internal carotids 842 and 843. Themain catheter 831 can be introduced in the manner hereinbefore describedwith respect to a saphenous vein graft. For example it can be introducedthrough the femoral artery in the leg and then advanced into the aorticarch up into the common carotid 841 until the occlusion balloon 669carried thereby is near the bifurcation as shown in FIG. 46. Theocclusion balloon 669 is then inflated to at least one atmosphere asshown in FIG. 47 to form a seal to occlude the common carotid 841 and totemporarily stop the flow of blood to the face and brain of the patientthrough the common carotid 841 and to provide a working space 845 distalof the occlusion balloon 669. The inflation is accomplished by suitablemeans as for example a syringe 846 secured to the balloon inflationfitting 687. Thereafter, a balloon-on-a-wire device 831 of the typeshown in FIG. 45 is introduced through the catheter port 833 andadvanced through the central lumen 657 of the main catheter 831 afterwhich the distal extremity is guided into the external carotid 842 so itis disposed beyond the bifurcation. The occlusion balloon 711 carried bythe distal extremity is then inflated by suitable means such as asyringe 847 secured to the attachment 836 to occlude the externalcarotid. As hereinbefore pointed out, the balloon 711 is an occlusionballoon that typically is inflated to a suitable occlusion pressure asfor example one to two atmospheres.

[0207] Another balloon-on-a-wire device such as the balloon-on-a-wiredevice 701 is then introduced through the catheter port 834 and advancedthrough the central passage or lumen 657 until it exits from the maincatheter 831 after which it is guided into the internal carotid 843 pastthe stenosis 844 so that the occlusion balloon 711 is distal of thestenosis 844. The occlusion balloon 711 is then inflated as shown by thedotted lines in FIG. 47 by the use of a syringe 848 secured to theinflation port carried by the removable valve attachment 741. Thus, thelimits of the working space or chamber 845 are defined by the occlusionballoons 669 and 711. As soon as the balloon 711 has been inflated, theballoon inflation lumen can be plugged in the manner hereinbeforedescribed by the use of a plug mandrel 756 (see FIG. 48). It should beappreciated even though the guide wire 702 and the occlusion balloon 711carried thereby may dislodge particles from the plaque forming thestenosis 844, the dislodged particles will not travel to the brainbecause the common carotid supplying blood to the internal carotid 843has been occluded by the occlusion balloon 669.

[0208] The removable valve attachment 741 can then be removed in themanner hereinbefore described so that the proximal extremity of theguide wire 702 is free of obstructions as shown in FIG. 68. Thereafterthe irrigation catheter 766 can be introduced over the guide wire 702and thence into the port 834 until its distal extremity extends beyondthe distal extremity of the main catheter 831. A therapeutic ballooncatheter 801 of the same type as hereinbefore described can then beintroduced through the irrigation catheter 766. It should be appreciatedthat if desired, the therapeutic balloon catheter can be preloaded intothe irrigation catheter 766 and the irrigation catheter 766 and thetherapeutic balloon catheter 801 can be introduced in unison. Assumingthat the irrigation catheter 766 has been introduced first, thetherapeutic balloon catheter 801 is introduced through the irrigationcatheter 766 until it extends beyond the distal extremity of theirrigation catheter 766 and is moved into the working space 845 untilthe therapeutic balloon 809 carried by the distal extremity thereof isin registration with the stenosis 844. The therapeutic balloon 809 isthen inflated as shown in FIG. 48 by the use of an inflation/deflationdevice 851 represented schematically by a syringe to a suitabletherapeutic pressure to compress the plaque forming the stenosis 844 todilate the stenosis to increase the size of the flow passage through thestenosis 844. The therapeutic balloon 809 can then be deflated. In theevent emboli 804 are created as hereinbefore described by the passage ofthe therapeutic balloon 809 through the stenosis, these emboli 804 canbe removed as shown in FIG. 49 by introducing a saline solution throughthe tube 819 and into the irrigation port 773 of the irrigation catheter766 to cause a saline solution to be discharged into the space formedbetween the two occlusion balloons 711 and 669. To achieve a moreeffective aspiration, the distal tip of the irrigation catheter 766 canbe moved through the stenosis 844 to just proximal of the occlusionballoon 711. Aspirate is removed through the aspiration port 689 throughthe use of the bulb 821 and the collection bag 824 to remove the salinesolution carrying with it the emboli 804 which may have been created anddeposit the same in the collection bag 824. This irrigation andaspiration can be carried on for a suitable period of time as forexample 5 to 30 seconds after which the occlusion balloons 711 in bothof the branches 842 and 843 can be deflated and the devices 701 and 835can be removed along with the catheter 801 carrying the therapeuticballoon 809. Similarly, the occlusion balloon 669 can be deflated topermit blood to flow into the common carotid 841 and the external andinternal carotids 842 and 843. Alternatively, the sequence of deflationof the balloons can be carried out in the manner hereinbefore describedin connection with a vessel without a bifurcation.

[0209] In the event it is desired to deliver a stent into the dilatedstenosis 844, this can be accomplished by reinflating the occlusionballoon 669 and then reinflating the occlusion balloons 711 in both ofthe branches after which a balloon stent delivery catheter 826 of thetype hereinbefore described can be delivered over the guide wire 702 inthe same manner as the therapeutic balloon catheter 766 and deliveredinto the desired location and then deployed in the dilated stenosis 844.After the stent 827 has been deposited and the balloon of the stentdelivery catheter 826 is deflated, the irrigation and aspirationprocedures hereinbefore described can be repeated to remove any emboliwithin the space formed between the occlusion balloons 711 and 669. Thestent delivery catheter 826 can be removed. After a suitable period ofirrigation and aspiration, as for example 5 to 30 seconds, the occlusionballoon 711 can be deflated after which the occlusion balloon 669 can bedeflated and the balloon-on-a-wire devices 701 and 835 removed alongwith the main catheter 652.

[0210] From the foregoing it can be seen that there has been provided anew and improved apparatus and a method for utilization of the samewhich makes it possible to carry out such stenosis opening procedureswithout the perfusion of blood. Complete stenosis procedures can becarried out in a period of time which is less than six minutes for eachcomplete procedure. Even though blood flow is occluded during thisperiod of time, this period of time is much less than the period oftime, as for example 30 minutes, required for a conventionalendoatherectomy. Thus, the procedures of the present invention can becarried out without endangering the patient, as for example the brain orthe heart of the patient.

[0211] The desire to eliminate the use of a large guiding catheter foruse with the main catheter 651 was hereinbefore discussed. Also, it washereinbefore disclosed that the main catheter 651 can be insertedindependently through a conventional sheath (not shown) in the femoralartery and thereafter a smaller conventional guiding catheter 786 isintroduced through the main catheter so that its distal extremity 789 isin the vessel. In other procedures it may be desirable to carry thisconcept still further, i.e., eliminating the need for a large guidingcatheter and also the need for a smaller guiding catheter to be advancedthrough the main catheter. To do this, it may be desirable to provide adistal extremity on the main catheter 651 which is shaped in apredetermined manner. For example, in the main catheter 651 a shown inFIG. 26A there is provided in the distal extremity a conventionalJudkins left shape and in the main catheter 651 b shown in FIG. 26Bthere is provided in the distal extremity a conventional Judkins rightshape. Other than the shaping of the distal extremities as hereinbeforedescribed, the main catheters 651 a and 651 b are constructed in amanner very similar to the catheter 651 and are provided with occlusionballoons 669 as shown.

[0212] Since the main catheters 651 a and 651 b are relatively flexible,they can be inserted into the femoral artery and have their distalextremities guided into the desired locations with the catheter beingselected for the appropriate bend to reach the desired location. Withthe main catheter having such capabilities, it is possible in connectionwith the present invention to advance the main catheter 651 into thedesired location by the use of a balloon-on-a-wire device of the typehereinbefore described, or alternatively over a conventional guide wire.This makes it possible to eliminate the use of a guiding catheter andtherefore substantially simplify the procedures of the present inventionand reduce the costs of such procedures.

[0213] In connection with the irrigation catheter 766 hereinbeforedescribed in FIG. 36, it should be appreciated as shown in FIGS. 36A and36B that irrigation catheters 766 a and 766 b can be provided which havesoft distal extremities to provide additional flexibility andtrackability and thereby reduce trauma in vessels through which they areintroduced. Thus in the irrigation catheter 766 a shown in FIG. 36A, themain portion of the flexible elongate tubular member 767 which can beconsidered to be the shaft can have a greater stiffness than the distalportion 767 a of the distal extremity. This can be readily accomplishedby utilizing a plastic such as Pebax and Hytrel of various desireddurometers. For example, the main shaft 767 can have a durometer rangingfrom 80-100 whereas the distal portion 767 a can have a durometerranging from 50-70. The cylindrical tip 767 c with a rounded forwardedge as shown is provided with a still lower durometer as for example35-55 durometer. Thus it can be seen that there has been provided anirrigation catheter which has a very soft tip and which has a distalportion in the distal extremity which is very flexible to permittracking and to reduce trauma.

[0214] In the irrigation catheter 766 b shown in FIG. 36, the shaft 767can have a durometer ranging from 80-100 whereas the portion 767 a canhave a durometer ranging from 60-70 and which has a portion 767 b formedof the same durometer material that is inclined inwardly and distally toreduce the size of the opening for the passage or lumen 768 as shown.The tip 767 which can be formed of a low durometer as for example 35-55durometer is mounted on the distal extremity 767 b. In order to enhancethe flow of irrigation fluid from the lumen 768 a plurality of holes 857is circumferentially distributed around the portion 767 a to augment theflow of irrigation fluid other than through the passage 856. The use ofthe embodiments 766 a and 766 b of the irrigation catheter is verysimilar to that hereinbefore described with the irrigation catheter 766shown in FIG. 36. It should be appreciated that if differing stiffnessesare desired for the main catheters 651 and 831, the same concepts asdisclosed for the irrigation catheter 766 can be utilized by selectingmaterials having desired durometers for various portions of thecatheters.

[0215] Another embodiment of the balloon-on-a-wire device is shown inFIGS. 51 and 52 in which the balloon-on-a wire device 901 is in manyrespects very similar to the balloon-on-a-wire device 701 shown in FIG.30 as hereinbefore described. The balloon-on-a-wire device 901 consistsof a flexible elongate member in the form of a guide wire 702 havingproximal and distal extremities 703 and 704 with a lumen 706 extendingtherethrough. A removable valve attachment or fitting 741 is provided onthe proximal extremity 907. A plug mandrel 756 is carried by theremovable valve attachment 741 for use in plugging the bore 706 whennecessary. An elastomeric balloon 906 is provided on the distalextremity 704 and is provided with proximal and distal extremities 907and 908. The balloon 906 has a suitable length as for example 10millimeters and a suitable diameter when collapsed or deflated of 1 mm.In order that the balloon 906 assume a generally rectangular shape asviewed in cross-section as shown in FIG. 51 with generally right anglecomers, the balloon 906 is provided with spaced-apart cylindricalregions 906 a and 906 b of greater thickness than an intermediateportion 906 c. For example, portions 906 a and 906 b can have athickness of 0.006″ to 0.010″ and portion 906 c of 0.003″ wallthickness. Such a balloon when inflated will have a squareness asillustrated by the dotted lines in FIG. 51. This squareness of theballoon comers helps to assure that emboli will not become entrappedbetween the balloon and the vessel wall and thereby will not roll by theballoon as it is moved in the vessel.

[0216] An elongate slot 911 is ground into the distal extremity of theguide wire 702 to a suitable depth which is in excess of one half of thediameter of the guide wire 702. The slot 911 is in communication withthe lumen 706 and opens into the interior of the balloon 906. A taperedcore wire 913 is mounted in the distal extremity 704 of the guide wire702. The core wire 913 is provided with a portion 913 a which has aprogressive decrease in diameter extending from the proximal extremityto a portion 913 b which is generally of a uniform diameter of asuitable size, as for example 0.003″ and is formed into a bend 916 andextends proximally along the slot 916 and proximally thereof where it issecured to the guide wire 702 by suitable means such as an adhesive 918.A coil spring 921 formed of a suitable material such as stainless steelor platinum extends over the slot 911 and proximally and distally of theslot 911 and is secured thereto by suitable means as solder 922.Positioned in this manner, the coil 921 generally circumscribes theinner circumference of the balloon 906 and serves to protect the balloon906 from any sharp edges as for example sharp edges formed by the slot911 in the coil wire 702. A tip coil 926 formed of a suitable radiopaquematerial such as a platinum or a platinum alloy is mounted over thedistal extremity of the guide wire 702 and secured thereto by suitablemeans such as solder 927. The distal extremity of the tip coil 926 whichmay have a suitable length, as for example 3 mm, is bonded to the corewire 913 b by a solder 928 which encloses the bend 916 and provides arounded forwardly protruding surface 929. The distal extremity 908 ofthe balloon 906 is secured to the coils 921 and 926 by an adhesive 931.Similarly, the proximal extremity 907 of the balloon 906 is secured tothe guide wire 702 and the portion 913 b by an adhesive 932.

[0217] The balloon-on-a-wire device 901 can be utilized in the samemanner as the balloon-on-a-wire device 701 hereinbefore described. It isbelieved that the balloon-on-a-wire device 901 has several desirablefeatures. For example the balloon 906 is protected from any sharp edgesby the coil spring 921. The slot 911, in addition to providing a meansfor inflating the balloon, also serves to provide a progressiveweakening of the distal extremity of the guide wire 702 to impartadditional flexibility to the distal extremity of the device.

[0218] By utilizing a balloon-on-a-wire constructions herein disclosed,it is possible to reduce the overall size of the apparatus for theprocedures. In view of the fact that guide wires having a size of 0.014″to 0.018″ are utilized in the present invention, many conventionaltherapeutic balloon devices can be utilized by advancing the same oversuch size guide wires. By the provision of removable valve attachmentsfor the balloon-on-awire devices, it is possible to use such devices forproviding the one or more balloons necessary for a procedure while atthe same time making it possible to utilize such devices as guide wiresafter removing the removable valve attachments on the proximalextremities. This makes it possible to utilize conventional stentdelivery catheters, ultrasound catheters and the like by advancing themover the already in place guide wires.

[0219] It should be appreciated that it may be possible to eliminate theuse of the occlusion balloons 711 which are distal of the proximalballoon carried by the main catheter and distal of the stenosis, sinceblood flow is occluded during the time that the occlusion balloon 669 isinflated.

[0220] Another embodiment of a catheter apparatus incorporating thepresent invention for treating occluded vessels is shown in FIGS. 53 and54. As shown therein, the catheter apparatus 951 consists of a flexibleelongate member 952 similar to those hereinbefore described which isprovided with proximal and distal extremities 953 and 954. Aconventional adapter 956 is mounted on the proximal extremity and isprovided with a Tuohy-Borst fitting 957 which is in communication with alarge central lumen 958 extending from the proximal extremity 953 to thedistal extremity 954. An aspiration fitting 961 is provided on theadapter 956 as well as an irrigation fitting 962, both of which are incommunication with the central lumen 958. However, it should beappreciated that if desired separate lumens can be provided in theflexible elongate member 952 for both of the fittings 961 and 962.

[0221] Self-expanding sealing means 966 is mounted on the distalextremity 954. This self-expanding sealing means 966 can take anysuitable form. For example, as shown it can consist of a braidedstructure 967 formed of a suitable shape memory material such as anickel titanium alloy that will attempt to expand to a predeterminedshape memory. Other than shape memory materials, other materials such asstainless steel, titanium or other materials can be utilized in thebraid 967 as long as they have the capability of expanding when theself-expanding seal means is released. Also it should be appreciatedthat the self-expanding seal means 966 can be comprised of an absorbentmaterial which when it absorbs saline or blood expands to form a seal.Such seals can be readily accomplished because it is only necessary toform a seal of approximately one atmosphere to prevent small particlesfrom moving downstream.

[0222] In order to prevent abrasion of a vessel, it is desirable tocover the braided structure 967 with a covering 968 of a suitablematerial such as a polymer which extends over the braided structure 967and which moves with the braided structure 967 as it expands andcontracts. The polymer can be of a suitable material such as silicone,C-flex, polyethylene or PET which would form a good sealing engagementwith the wall of the artery.

[0223] Means is provided for compressing the self-expanding sealingmeans 966 so that the apparatus can be inserted into the vessel 781 andconsists of an elongate sleeve 1071 having proximal and distalextremities 1072 and 1073 and a bore 1074 extending from the proximalextremity 1072 to the distal extremity 1073. A collar 1076 is mounted onthe proximal extremity 1072 of the sleeve 1071 and is positioned nearthe adapter 956. The collar 1076 serves as means for retracting thesleeve as shown in FIG. 54 to uncover the self-expanding sealing means966 after the catheter has been deployed to permit the self-expandingsealing means 966 to expand and form a seal with the arterial vesseladjacent the stenosis to be treated.

[0224] Another embodiment of a catheter apparatus for treating occludedvessels incorporating the present invention is shown in FIGS. 55 and 56.As shown therein, the apparatus 1081 consists of a guiding catheter 1082having proximal and distal extremities 1083 and 1084. As shown, thedistal extremity 1083 is provided with a pre-formed bend of aconventional type. A conventional attachment 1086 is mounted on theproximal extremity 1083. Self-expanding seal means 1091 is mounted onthe distal extremity 1084 and is of the type hereinbefore described inconnection with the embodiments shown in FIGS. 53 and 54. A sleeve 1096similar to the sleeve 1071 of the previous embodiment is provided in thepresent embodiment for encasing the self-expanding seal means 1091 andfor releasing the same after it has been disposed in an appropriateposition within a vessel adjacent the occlusion to be treated. Thus asleeve 1096 is provided having proximal and distal extremities 1097 and1098 and having a bore 1099 extending from the proximal extremity to thedistal extremity which is sized so that it can receive the guidecatheter 1082. It is provided with a collar 1101 on its proximalextremity which is adapted to be disposed outside the patient and whichis adapted to be grasped by the physician for pulling the sleeve 1096proximally to uncover the self-expanding seal 1091 after the apparatushas been deployed to permit the self-expansion of the sealing means 1091to form a seal with the vessel wall is shown in FIG. 56.

[0225] In accordance with the hereinbefore described descriptions, it isapparent that the apparatus can be readily deployed and serve the samefunction as the main catheter. To accomplish this, the assembly 1081 canbe introduced into the femoral artery and the distal extremity advancedinto the desired location in the arterial vessel. After it has beenproperly positioned, the physician can retract the sleeve 1096 to permitthe self-expanding seal means 1091 to expand and to form a seal with thewall of the arterial vessel to occlude the arterial vessel and interruptthe flow of blood in the vessel to provide a working space distal of theocclusion formed. This prevents small particles which may thereafter bedislodged from moving downstream. Since a central lumen is available,the therapeutic procedures hereinbefore described can be employed withthe catheter apparatus shown in FIGS. 53, 54, 55 and 56.

[0226] Thus it can be seen that it has been possible to substantiallyreduce the complexity of the apparatus utilized in such procedures. Thisreduces the cost of the apparatus used therein as well as reducing thetime required for performing such procedures making the procedures lesscostly.

[0227] It will be appreciated that certain variations of the presentinvention may suggest themselves to those skilled in the art. Theforegoing detailed description is to be clearly understood as given byway of illustration, the spirit and scope of this invention beinglimited solely by the appended claims.

What is claimed is:
 1. A method of protecting a patient fromembolization during a percutaneous procedure on a vessel, comprising thesteps of: providing a guidewire having proximal and distal ends, aproximal and a distal region, an expandable filter associated with thedistal region, and a removable sheath which covers the expandable filterand is slidable over the guidewire; introducing the distal end of theguidewire into the patient's vessel with the sheath covering theexpandable filter, and positioning the filter downstream of a region ofinterest, wherein the sheath and guidewire cross the region of interest;sliding the sheath toward the proximal end of the guidewire and removingthe sheath from the vessel, wherein the expandable filter is uncovered;deploying the filter; advancing over the guidewire a stent-deploymentcatheter to the region of interest; and expanding the stent at theregion of interest, wherein embolic material is generated and capturedbefore the expandable filter is removed from the patient's vessel. 2.The method of claim 1, further comprising the steps of: removing thestent & deployment catheter from the vessel; advancing the sheath intothe vessel over the guidewire until the sheath covers the expandablefilter; and removing the guidewire and sheath from the vessel.
 3. Themethod of claim 1, wherein the stent is deployed by inflation of aballoon.
 4. The method of claim 1, wherein the stent-deployment catheteris a rapid exchange catheter.
 5. The method of claim 1, wherein theexpandable filter comprises a plurality of struts, each strut having aproximal end in contact with the guidewire and a distal end in contactwith the guidewire, and wherein the struts expand to the shape of aneggbeater.
 6. The method of claim 1, wherein the expandable filterincludes a filter mesh.
 7. The method of claim 1, wherein the expandablefilter comprises a plurality of radially biased struts.
 8. The method ofclaim 1, wherein the expandable filter comprises a plurality of radiallyexpandable struts which are operable to expand radially outwardly.
 9. Apercutaneous system having filter and stent deployment capabilities,comprising: a guidewire having proximal and distal ends, a proximal anddistal region, and an expandable filter associated with the distalregion; a sheath which is shaped to receive the guidewire and retain thefilter in a contracted condition, and to slidably release the filter toan expanded condition when the sheath moves toward the proximal end ofthe guide wire; a catheter having a proximal and a distal end, aproximal and a distal region, and a lumen which slidably receives theguidewire; and an expandable stent disposed about the distal region ofthe catheter, the stent having a first diameter which permitsintraluminal delivery of the stent into a body passageway and whichplaces the stent in close proximity to the catheter, and having a secondexpanded diameter adapted to substantially engage a wall of the bodypassageway, wherein, during use, the guidewire is positioned across aregion of interest, the filter is expanded, and the stent is deployedwithin the region of interest and remains in place after removal of thecatheter from the vessel.
 10. The system of claim 9 wherein theexpandable filter comprises an expansion frame and a filter meshattached to the expansion frame.
 11. The system of claim 10, wherein theexpansion frame comprises a plurality of struts which, upon activation,bend outwardly to the enlarged condition.
 12. The system of claim 11,wherein the guidewire includes a distal segment which can be movedlongitudinally relative to a proximal segment, and wherein the proximalend of each strut is in contact with the proximal segment and a distalend of each strut is in contact with the distal segment, and wherein thestruts expand radially when the distal segment is pulled toward theproximal region of the catheter.
 13. The system of claim 10, wherein theexpansion frame comprises radially biased struts attached to an outersurface of the catheter.
 14. The system of claim 13, wherein a proximalend of each strut is in contact with the catheter and the distal end ofeach strut is in contact with the catheter, and wherein the strutsexpand to the shape of an eggbeater.
 15. The system of claim 10, whereinthe expansion frame comprises an inflation seal.
 16. The system of claim15, further comprising an inflation system comprising a first lumenadapted to receive pressurized fluid and a second lumen adapted toevacuate gas, and wherein the inflation seal further includes an entryport in fluid communication with the first lumen of the inflation systemand an exit port in fluid communication with the second lumen of theinflation system, so that when fluid is advanced through the firstlumen, the fluid enters the inflation seal and forces gas from theinflation seal through the second lumen, thereby purging the system ofgas.
 17. The system of claim 15, wherein the inflation seal comprises atubular balloon which encloses a chamber and wherein the entry port andexit port are in close proximity, and wherein a septum is disposedbetween the entry and exit ports.
 18. The system of claim 9, wherein thestent and the filter are self-expanding.
 19. The system of claim 9,wherein the stent is removable.
 20. The system of claim 9, wherein thestent is self-expanding.
 21. The system of claim 9, wherein the stentcomprises stainless steel material.
 22. The system of claim 9, whereinthe stent comprises nitinol material.
 23. The system of claim 9, whereinthe stent has a shape selected from the group consisting of a tube, asheet, a wire, a mesh, and a spring.
 24. The system of claim 9, whereinthe sheath is shaped to receive the catheter and retain the stent at thefirst diameter.